CB-599: surface a capacity refusal's reason instead of a bare 500

PlacementException extends IllegalStateException, which neither BridgedApp
nor BridgeMcp's spawn catch blocks handled, so a maxLoad/quarantine/
all-exhausted refusal fell through to a blank 500 on REST and lost its
message on MCP. Catch it on both surfaces, ahead of the unrelated
IllegalArgumentException(unknown_profile) mapping, and return its message
structured: REST as {"error":"no_capacity","detail":...} with status 503,
MCP as an isError result prefixed "no capacity: ...".

bridged/bridged.example.yaml

@@ -434,10 +434,14 @@ guard:
 # on a durable per-target queue (agent.<target>.inbox) and survive a restart — the broker
 # redelivers anything the primary had not yet drained. Production default is LavinMQ; a stock
 # RabbitMQ speaks the same AMQP 0-9-1, so it is a URI-only swap.
-#   uri → AMQP connection URI. No trailing slash ⇒ the default vhost "/"; an empty path ("/")
-#         is vhost "" and will NOT connect. Encode a named vhost as .../%2Fmyvhost.
+#   uri      → AMQP connection URI. No trailing slash ⇒ the default vhost "/"; an empty path ("/")
+#              is vhost "" and will NOT connect. Encode a named vhost as .../%2Fmyvhost.
+#   prefetch → CB-527: consumer basicQos, capping how many unacked messages the inbox holds
+#              in-heap per owned target (the rest sits on the broker's durable queue instead of
+#              growing the JVM heap). Default 32 when omitted.
 # broker:
 #   uri: amqp://guest:guest@127.0.0.1:5672
+#   prefetch: 32
 
 # Active push-to-primary (CB-307 Stage 3). When a worker reply lands with no open bridge_send,
 # the ReplyPushLoop injects a *drain nudge* (never the payload) into the primary's own herdr

bridged/src/main/java/dev/ltms/bridged/Bridged.java

@@ -352,8 +352,9 @@ public final class Bridged {
         // connection, so keep the reference to close it in the ordered shutdown hook.
         final ReplyInbox replyInbox;
         if (cfg.broker() != null && cfg.broker().isConfigured()) {
-            replyInbox = AmqpReplyInbox.open(cfg.broker().uri());
-            log.info("reply inbox: AMQP broker (durable) at {}", cfg.broker().uri());
+            replyInbox = AmqpReplyInbox.open(cfg.broker().uri(), cfg.broker().prefetchOrDefault());
+            log.info("reply inbox: AMQP broker (durable) at {} (prefetch={})",
+                    cfg.broker().uri(), cfg.broker().prefetchOrDefault());
         } else {
             replyInbox = new InMemoryReplyInbox();
             log.info("reply inbox: in-memory (soft-state)");

bridged/src/main/java/dev/ltms/bridged/config/BridgedConfig.java

@@ -5,6 +5,7 @@ import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+import dev.ltms.bridged.msg.AmqpReplyInbox;
 import dev.ltms.bridged.peer.MemberRole;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -532,16 +533,24 @@ public record BridgedConfig(
      * stays soft-state. Production default is LavinMQ; a stock RabbitMQ speaks the same AMQP 0-9-1
      * and is a URI-only swap.
      *
-     * @param uri AMQP connection URI, e.g. {@code amqp://guest:guest@127.0.0.1:5672/}. Blank/{@code null}
-     *            ⇒ the broker block is treated as absent (in-memory adapter).
+     * @param uri      AMQP connection URI, e.g. {@code amqp://guest:guest@127.0.0.1:5672/}. Blank/
+     *                 {@code null} ⇒ the broker block is treated as absent (in-memory adapter).
+     * @param prefetch CB-527: the consumer's {@code basicQos} prefetch count, bounding how many
+     *                 unacked messages the AMQP inbox holds in-heap per owned target. {@code null}/
+     *                 non-positive ⇒ {@link AmqpReplyInbox#DEFAULT_PREFETCH}.
      */
     @JsonIgnoreProperties(ignoreUnknown = true)
-    public record Broker(String uri) {
+    public record Broker(String uri, Integer prefetch) {
 
         /** True when a usable broker URI is configured (an empty block does not enable AMQP). */
         public boolean isConfigured() {
             return uri != null && !uri.isBlank();
         }
+
+        /** The prefetch to use, defaulting to {@link AmqpReplyInbox#DEFAULT_PREFETCH} when unset. */
+        public int prefetchOrDefault() {
+            return (prefetch != null && prefetch > 0) ? prefetch : AmqpReplyInbox.DEFAULT_PREFETCH;
+        }
     }
 
     /**

bridged/src/main/java/dev/ltms/bridged/mcp/BridgeMcp.java

@@ -15,6 +15,7 @@ import dev.ltms.bridged.msg.MessageService;
 import dev.ltms.bridged.msg.Rendezvous;
 import dev.ltms.bridged.peer.PeerUnreachableException;
 import dev.ltms.bridged.placement.BackendQuarantine;
+import dev.ltms.bridged.placement.PlacementException;
 import dev.ltms.bridged.session.SessionManager;
 import dev.ltms.bridged.session.MemberSession;
 import dev.ltms.bridged.session.WorktreeRequest;
@@ -692,6 +693,10 @@ public final class BridgeMcp {
             return text(json(memberView(member)));
         } catch (GuardException e) {
             return error("subscription boundary: " + e.getMessage());
+        } catch (PlacementException e) {
+            // CB-599: no candidate had capacity (maxLoad, quarantine, or all-exhausted) — distinct
+            // from "profile does not exist" below.
+            return error("no capacity: " + e.getMessage());
         } catch (IllegalArgumentException e) {
             return error(e.getMessage()); // unknown / no-default profile, or a refused resumeSessionId
         } catch (PeerUnreachableException e) {

bridged/src/main/java/dev/ltms/bridged/msg/AmqpReplyInbox.java

@@ -7,6 +7,7 @@ import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.DeliverCallback;
 import com.rabbitmq.client.Recoverable;
 import com.rabbitmq.client.RecoveryListener;
+import com.rabbitmq.client.Return;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -14,7 +15,13 @@ import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.NavigableMap;
+import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 /**
  * AMQP-backed {@link ReplyInbox} (CB-307 Stage 2): genuine cross-restart durability behind the same
@@ -29,6 +36,27 @@ import java.util.concurrent.ConcurrentHashMap;
  * leaves them on the broker — it redelivers on reconnect. That is the durability the in-memory
  * adapter cannot give, with the port contract preserved.
  *
+ * <p><strong>Prefetch bounds the held backlog (CB-527).</strong> The consumer channel calls
+ * {@code basicQos} with a configurable prefetch count ({@link #DEFAULT_PREFETCH} unless the caller
+ * passes another value to {@link #open(String, int)}) before starting any consumer. Without a bound,
+ * the broker pushes its entire queue into {@link #held} the instant a target is {@link #own owned},
+ * so an undrained primary grows the JVM heap without limit and any queue-level control
+ * ({@code x-max-length}, per-message TTL) never fires because the queue never actually holds a
+ * backlog. Prefetch keeps the backlog where it is visible — on the broker — until the owner drains it.
+ *
+ * <p><strong>Publishes require a confirmed, routable delivery (CB-528).</strong> {@link #publish}
+ * runs on a channel separate from the consume/ack channel ({@link #channel}), so a slow or blocked
+ * publish confirm can never hold {@link #channelLock} and stall an ack — the ack path never waits on
+ * a publish confirm. That publish channel is in publisher-confirm mode and every publish sets the
+ * {@code mandatory} flag, so an unroutable publish (queue not declared, e.g. the owner never called
+ * {@link #own}) is returned by the broker instead of silently dropped. The broker sends the
+ * <em>return</em> for an unroutable message before the <em>confirm</em> that covers it — the ack/nack
+ * callback checks the returned-set at confirm time rather than assuming an ack means routed — so
+ * "confirmed" here means "durably queued", not merely "accepted by the broker". A returned or nacked
+ * (or un-confirmed within the timeout) publish surfaces as an {@link IllegalStateException} on the
+ * caller's thread; the caller — {@link MessageService#reply} — must not report success for a
+ * black-holed reply.
+ *
  * <p><strong>Ownership is explicit.</strong> {@link #own} declares the queue and starts the consumer;
  * {@link #release} cancels it. {@link #publish} sends to the queue but does <em>not</em> imply ownership
  * and does not attach a consumer. This split is required by CB-308 federation, where one gateway may
@@ -54,6 +82,12 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
     private static final String QUEUE_PREFIX = "agent.";
     private static final String QUEUE_SUFFIX = ".inbox";
 
+    /** CB-527: the prefetch used when a caller does not pass an explicit value to {@link #open(String, int)}. */
+    public static final int DEFAULT_PREFETCH = 32;
+
+    /** How long {@link #publish} waits for its publisher confirm before failing the call (CB-528). */
+    private static final long CONFIRM_TIMEOUT_MS = 10_000L;
+
     private final Connection connection;
     private final Channel channel;
     /** All channel operations (publish/declare/ack/cancel) serialize on this — a Channel is not thread-safe. */
@@ -63,39 +97,87 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
     /** Targets whose queue is declared and consumer is running, mapped to their broker consumer tag. */
     private final ConcurrentHashMap<String, String> consumerTags = new ConcurrentHashMap<>();
 
+    /**
+     * CB-528: a dedicated channel for {@link #publish}, kept separate from {@link #channel} (consume
+     * + ack) so a publish confirm round trip never blocks under {@link #channelLock} and stalls an ack.
+     */
+    private final Channel publishChannel;
+    private final Object publishChannelLock = new Object();
+    /** In-flight publishes awaiting their confirm, keyed by the publish channel's sequence number. */
+    private final ConcurrentSkipListMap<Long, Pending> pendingBySeq = new ConcurrentSkipListMap<>();
+    /**
+     * The same in-flight publishes, keyed by {@code msgId} — a broker {@code Return} carries no delivery
+     * tag. Assumes {@code msgId} is unique per in-flight publish: a second {@link #publish} for a
+     * {@code msgId} still awaiting its confirm would overwrite this entry and misdirect
+     * {@link #onReturn}'s lookup. Not reachable today — {@code MessageService.reply} generates a fresh
+     * {@code UUID} per call — so no guard is added for it.
+     */
+    private final ConcurrentHashMap<String, Pending> pendingByMsgId = new ConcurrentHashMap<>();
+
     /** A message pulled off the broker but not yet acked: its delivery-tag plus the port payload. */
     private record Held(long deliveryTag, InboxMessage message) {}
 
-    /** Connect to {@code uri} (e.g. {@code amqp://guest:guest@127.0.0.1:5672/}) and open the inbox. */
+    /** A publish awaiting its confirm; {@link #returned} records whether the broker already returned it. */
+    private static final class Pending {
+        final String msgId;
+        final CompletableFuture<Void> confirmed = new CompletableFuture<>();
+        volatile boolean returned;
+
+        Pending(String msgId) {
+            this.msgId = msgId;
+        }
+    }
+
+    /** Connect to {@code uri} (e.g. {@code amqp://guest:guest@127.0.0.1:5672/}) with {@link #DEFAULT_PREFETCH}. */
     public static AmqpReplyInbox open(String uri) {
+        return open(uri, DEFAULT_PREFETCH);
+    }
+
+    /** As {@link #open(String)}, with an explicit consumer prefetch (CB-527: caps the held backlog per target). */
+    public static AmqpReplyInbox open(String uri, int prefetch) {
         try {
             ConnectionFactory factory = new ConnectionFactory();
             factory.setUri(uri);
             // Self-heal transient blips; topology recovery re-declares queues and re-attaches consumers.
             factory.setAutomaticRecoveryEnabled(true);
             factory.setTopologyRecoveryEnabled(true);
-            return new AmqpReplyInbox(factory.newConnection("bridged-reply-inbox"));
+            return new AmqpReplyInbox(factory.newConnection("bridged-reply-inbox"), prefetch);
         } catch (Exception e) {
             throw new IllegalStateException("cannot connect to AMQP broker at " + uri, e);
         }
     }
 
-    /** Wrap an already-open connection (injection seam for the contract test). */
+    /** Wrap an already-open connection with {@link #DEFAULT_PREFETCH} (injection seam for the contract test). */
     AmqpReplyInbox(Connection connection) {
+        this(connection, DEFAULT_PREFETCH);
+    }
+
+    /** As above, with an explicit prefetch (injection seam for the contract test). */
+    AmqpReplyInbox(Connection connection, int prefetch) {
         this.connection = connection;
         try {
             this.channel = connection.createChannel();
+            // CB-527: bound the held backlog per owned target — must be set before any own()/basicConsume.
+            this.channel.basicQos(prefetch);
+            this.publishChannel = connection.createChannel();
+            this.publishChannel.confirmSelect();
+            this.publishChannel.addReturnListener(this::onReturn);
+            this.publishChannel.addConfirmListener(this::onAck, this::onNack);
         } catch (IOException e) {
             throw new IllegalStateException("cannot open AMQP channel", e);
         }
         // On automatic recovery the broker redelivers unacked messages with FRESH delivery-tags; the
         // tags we were holding are now stale. Drop the held snapshot so the re-attached consumer
-        // repopulates it with valid tags (dedup by msgId still prevents any double-queue).
+        // repopulates it with valid tags (dedup by msgId still prevents any double-queue). Any publish
+        // confirm still in flight when the connection dropped is equally stale — its sequence number
+        // meant nothing on the old channel and means nothing on the recovered one, so fail it now
+        // rather than let it silently ride out CONFIRM_TIMEOUT_MS.
         if (connection instanceof Recoverable recoverable) {
             recoverable.addRecoveryListener(new RecoveryListener() {
                 @Override
                 public void handleRecovery(Recoverable recoverable) {
                     held.clear();
+                    failPendingPublishesOnRecovery();
                     log.info("AMQP connection recovered; cleared held replies for fresh redelivery");
                 }
 
@@ -141,6 +223,12 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
         }
     }
 
+    /**
+     * Publish {@code content} and block until the broker's publisher confirm for it lands (CB-528).
+     * Throws {@link IllegalStateException} if the message is returned as unroutable, nacked, or not
+     * confirmed within {@link #CONFIRM_TIMEOUT_MS} — the caller must treat that as a failed publish,
+     * not a lost-and-forgotten one.
+     */
     @Override
     public void publish(String target, String msgId, String content) {
         AMQP.BasicProperties props = new AMQP.BasicProperties.Builder()
@@ -148,12 +236,35 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
                 .deliveryMode(2)                   // persistent — survives a broker restart
                 .contentType("text/plain")
                 .build();
-        try {
-            synchronized (channelLock) {
-                channel.basicPublish("", queueName(target), props, content.getBytes(StandardCharsets.UTF_8));
+        Pending pending = new Pending(msgId);
+        long seq;
+        synchronized (publishChannelLock) {
+            seq = publishChannel.getNextPublishSeqNo();
+            pendingBySeq.put(seq, pending);
+            pendingByMsgId.put(msgId, pending);
+            try {
+                publishChannel.basicPublish("", queueName(target), true, props,
+                        content.getBytes(StandardCharsets.UTF_8));
+            } catch (IOException e) {
+                pendingBySeq.remove(seq, pending);
+                pendingByMsgId.remove(msgId, pending);
+                throw new IllegalStateException("cannot publish reply to " + queueName(target), e);
             }
-        } catch (IOException e) {
-            throw new IllegalStateException("cannot publish reply to " + queueName(target), e);
+        }
+        try {
+            pending.confirmed.get(CONFIRM_TIMEOUT_MS, TimeUnit.MILLISECONDS);
+        } catch (ExecutionException e) {
+            Throwable cause = e.getCause();
+            throw cause instanceof RuntimeException re ? re : new IllegalStateException(cause);
+        } catch (TimeoutException e) {
+            throw new IllegalStateException("publish confirm for reply " + msgId + " to " + queueName(target)
+                    + " timed out after " + CONFIRM_TIMEOUT_MS + "ms — broker may be unreachable or overloaded", e);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new IllegalStateException("interrupted awaiting publish confirm for " + msgId, e);
+        } finally {
+            pendingBySeq.remove(seq, pending);
+            pendingByMsgId.remove(msgId, pending);
         }
     }
 
@@ -222,17 +333,115 @@ public final class AmqpReplyInbox implements ReplyInbox, AutoCloseable {
         };
     }
 
+    /** Broker return for an unroutable {@code mandatory} publish — arrives BEFORE its confirm (CB-528). */
+    private void onReturn(Return r) {
+        String msgId = r.getProperties() == null ? null : r.getProperties().getMessageId();
+        Pending pending = msgId == null ? null : pendingByMsgId.get(msgId);
+        if (pending != null) {
+            pending.returned = true;
+        } else {
+            log.warn("AMQP return for reply {} (routingKey={}, {} {}) with no matching in-flight publish"
+                    + " — already resolved by a prior confirm", msgId, r.getRoutingKey(), r.getReplyCode(),
+                    r.getReplyText());
+        }
+    }
+
+    private void onAck(long seq, boolean multiple) {
+        resolveConfirm(seq, multiple, true);
+    }
+
+    private void onNack(long seq, boolean multiple) {
+        resolveConfirm(seq, multiple, false);
+    }
+
+    /**
+     * Resolve every pending publish covered by this confirm (a single seq, or — {@code multiple} —
+     * every seq up to and including it). Checks {@link Pending#returned} at confirm time: since the
+     * broker's return for an unroutable message always precedes its confirm, an ack that arrives after
+     * a return means "confirmed but never routed", not "durably queued".
+     */
+    private void resolveConfirm(long seq, boolean multiple, boolean ack) {
+        NavigableMap<Long, Pending> covered = multiple
+                ? pendingBySeq.headMap(seq, true)
+                : pendingBySeq.subMap(seq, true, seq, true);
+        for (var it = covered.entrySet().iterator(); it.hasNext(); ) {
+            Pending pending = it.next().getValue();
+            it.remove();
+            pendingByMsgId.remove(pending.msgId, pending);
+            if (ack && !pending.returned) {
+                pending.confirmed.complete(null);
+            } else if (ack) {
+                pending.confirmed.completeExceptionally(new IllegalStateException(
+                        "reply " + pending.msgId + " was returned as unroutable (queue not declared/owned)"));
+            } else {
+                pending.confirmed.completeExceptionally(new IllegalStateException(
+                        "broker nacked publish of reply " + pending.msgId));
+            }
+        }
+    }
+
+    /**
+     * Fail every publish still awaiting its confirm — their sequence numbers are stale after recovery.
+     * Guarded by {@link #publishChannelLock}, the same lock {@link #publish} holds while it takes its
+     * sequence number and registers its {@link Pending}: without it, a {@link #publish} that starts
+     * after the connection has already recovered (so it publishes — and will be confirmed — on the
+     * <em>new</em> channel) can register between this sweep's iteration and its clear, and this sweep
+     * then fails a publish that actually succeeded. {@link #publish} only holds the lock for the
+     * seq/map-put/{@code basicPublish} — it awaits the confirm outside it — so this sweep can only ever
+     * wait for an in-flight {@code basicPublish} call to return, never for a broker round trip. No
+     * deadlock.
+     *
+     * <p>Package-private (rather than {@code private}) only so the unit test can drive it directly
+     * against a concurrent {@link #publish} without a live broker reconnect.
+     */
+    void failPendingPublishesOnRecovery() {
+        synchronized (publishChannelLock) {
+            for (var it = pendingBySeq.entrySet().iterator(); it.hasNext(); ) {
+                Pending pending = it.next().getValue();
+                it.remove();
+                pendingByMsgId.remove(pending.msgId, pending);
+                pending.confirmed.completeExceptionally(new IllegalStateException(
+                        "AMQP connection recovered mid-publish; confirm status of reply " + pending.msgId
+                                + " is unknown"));
+            }
+        }
+    }
+
+    /**
+     * Fail every publish still awaiting its confirm with a clear, immediate error instead of leaving it
+     * to time out after {@link #CONFIRM_TIMEOUT_MS} once the channels are closed underneath it. Guarded
+     * by {@link #publishChannelLock} for the same reason as {@link #failPendingPublishesOnRecovery}.
+     */
+    private void failPendingPublishesOnClose() {
+        synchronized (publishChannelLock) {
+            for (var it = pendingBySeq.entrySet().iterator(); it.hasNext(); ) {
+                Pending pending = it.next().getValue();
+                it.remove();
+                pendingByMsgId.remove(pending.msgId, pending);
+                pending.confirmed.completeExceptionally(new IllegalStateException(
+                        "AMQP reply inbox closed while publish of reply " + pending.msgId
+                                + " was still awaiting its confirm"));
+            }
+        }
+    }
+
     private static String queueName(String target) {
         return QUEUE_PREFIX + target + QUEUE_SUFFIX;
     }
 
     @Override
     public void close() {
+        failPendingPublishesOnClose();
         try {
             channel.close();
         } catch (Exception e) {
             log.debug("AMQP channel close: {}", e.toString());
         }
+        try {
+            publishChannel.close();
+        } catch (Exception e) {
+            log.debug("AMQP publish channel close: {}", e.toString());
+        }
         try {
             connection.close();
         } catch (Exception e) {

bridged/src/main/java/dev/ltms/bridged/msg/ReplyPushLoop.java

@@ -8,6 +8,8 @@ import dev.ltms.bridged.metrics.Metrics;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -16,35 +18,43 @@ import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
 
 /**
- * Mechanism (b) of CB-307: a dedicated, status-gated push loop that nudges the primary's own
- * herdr pane when a worker reply lands with no live {@code bridge_send} to resolve it.
+ * A status-gated push loop that nudges a lead's own herdr pane when it has uncollected work
+ * waiting: a worker reply queued with no live {@code bridge_send} to resolve it (CB-307), or an
+ * async delegation ticket ({@code bridge_send(wait:false)}) that reached a terminal phase
+ * (CB-588).
  *
- * <p>The loop is triggered by {@link #onReplyQueued(String)} (called from
- * {@link MessageService#reply} after the durable inbox publish). It checks four conditions
- * at each tick via {@link #decide(String, int)}, then either injects a drain nudge,
- * waits for the primary to become injectable, or stops reminding.
+ * <p><strong>CB-590: one schedule per lead.</strong> Both kinds of work are triggered through
+ * their own entry point — {@link #onReplyQueued(String)} and
+ * {@link #onTicketTerminal(String, String, boolean)} — but both resolve the lead that should be
+ * nudged and coalesce onto a single per-lead reminder schedule, tracked in {@link #activeLeads}.
+ * Earlier this was two independent schedules (one keyed by worker target for replies, one keyed
+ * by lead for tickets) that could both decide to inject into the same pane in the same window —
+ * a race, not routine behaviour, but the expensive kind: it interrupts the lead's live turn
+ * twice. Collapsing to one schedule per lead makes that structurally impossible: at most one
+ * scheduled tick chain is ever live for a given lead (guarded by {@link #activeLeads}'
+ * compare-and-set), so at most one {@code agents.send} to that lead's pane is ever in flight.
  *
- * <p>Bounded: at most {@link #maxReminders} nudges per target, with a configurable backoff
- * between them. The reply is never lost — the durable inbox is the backstop.
- *
- * <p><strong>CB-588 ticket nudges.</strong> {@link #onTicketTerminal(String, String, boolean)} is a
- * second, independent entry point for an async delegation ticket ({@code bridge_send(wait:false)})
- * reaching a terminal phase. That path takes the rendezvous fast path in {@link MessageService#reply}
- * and never reaches {@link #onReplyQueued}, so without this the lead's own charter — prefer
- * {@code wait:false} for anything non-trivial — was exactly the mode this loop failed to cover. It
- * reuses the same status gating, bounded/backoff reminders, and metrics, keyed by the nudge-receiving
- * lead terminal rather than the worker target so several tickets finishing together coalesce into one
- * nudge. The two entry points do not interact: {@link #onReplyQueued} / {@link #decide} / their nudge
- * text and bound are unchanged.
+ * <p>Each tick examines <em>everything</em> pending for that lead — reply targets whose inbox
+ * still holds an unacked message ({@link #pendingReplies}) and tickets not yet collected
+ * ({@link #pendingTickets}) — and sends at most one combined nudge per tick
+ * ({@link #injectNudge(String, int, int)}). Work that arrives while the lead is busy is never
+ * lost: it is re-read fresh on every tick until the lead is injectable or its own reminder cap
+ * ({@link #maxReminders}) is reached — reply and ticket work each spend from their own budget, so
+ * one source exhausting its cap does not stop nudges about the other (post-CB-590 regression fix;
+ * see {@link #decide}) — whichever the durable inbox / pending-ticket set doesn't already answer
+ * via {@code STOP}.
  */
 public final class ReplyPushLoop {
 
     private static final Logger log = LoggerFactory.getLogger(ReplyPushLoop.class);
     static final String NUDGE_FORMAT = "Worker %s returned a reply — run bridge_poll(target=%s) to collect it";
-    /** CB-588: singular form, one uncollected ticket. */
+    /** Coalesced form, several uncollected replies for the same lead. */
+    static final String REPLIES_NUDGE_FORMAT =
+            "%d workers returned replies — run bridge_poll(target=...) for each to collect them: %s";
+    /** Singular form, one uncollected ticket. */
     static final String TICKET_NUDGE_FORMAT =
             "Ticket %s finished%s — run bridge_poll(ticket=%s) to collect it";
-    /** CB-588: coalesced form, several uncollected tickets for the same lead. */
+    /** Coalesced form, several uncollected tickets for the same lead. */
     static final String TICKETS_NUDGE_FORMAT =
             "%d tickets finished%s — run bridge_poll(ticket=...) for each to collect them: %s";
 
@@ -56,11 +66,11 @@ public final class ReplyPushLoop {
     private final long backoffMs;
     private final Metrics metrics; // CB-512: nullable — no registry in unit tests
 
-    /** Track targets that have an active schedule. */
-    private final ConcurrentHashMap<String, Boolean> activeTargets = new ConcurrentHashMap<>();
-    /** CB-588: tickets that have gone terminal but not yet been polled, keyed by ticket. */
+    /** Worker targets with a reply queued, and the lead to nudge about it, keyed by target. */
+    private final ConcurrentHashMap<String, String> pendingReplies = new ConcurrentHashMap<>();
+    /** Tickets that have gone terminal but not yet been polled, keyed by ticket. */
     private final ConcurrentHashMap<String, PendingTicket> pendingTickets = new ConcurrentHashMap<>();
-    /** CB-588: leads with an active ticket-reminder schedule. */
+    /** CB-590: leads with an active combined reminder schedule (replies and/or tickets). */
     private final ConcurrentHashMap<String, Boolean> activeLeads = new ConcurrentHashMap<>();
 
     public ReplyPushLoop(PrimaryRegistry primaryRegistry, AgentControl agents, ReplyInbox inbox,
@@ -89,178 +99,79 @@ public final class ReplyPushLoop {
         }
     }
 
-    // --- decision logic (package-private for unit-testing) -------------------------------------
+    // --- pending-work lookups (package-private for unit-testing) -------------------------------
 
-    /** The action the loop should take for a target at the given reminder count. */
+    /** The action the loop should take for a lead at the given reminder count. */
     enum Action { INJECT, WAIT_BUSY, STOP }
 
     /**
-     * Pure decision function: examine the current state and return what the loop should do.
-     *
-     * @param target        the worker session (target terminal id)
-     * @param reminderCount how many nudges have been sent so far for this target
-     * @return the action the caller should take
+     * Reply targets still pending for {@code lead} — registered via {@link #onReplyQueued} and
+     * whose inbox still holds an unacked message. A target whose inbox has since drained (acked,
+     * or collected via a live {@code bridge_send} rendezvous instead) is dropped from
+     * {@link #pendingReplies} here rather than lingering forever; there is no explicit "reply
+     * collected" callback the way {@link #ticketCollected} exists for tickets, so the inbox itself
+     * is the only signal.
      */
-    Action decide(String target, int reminderCount) {
-        // CB-532: the destination is per-delegation — the lead that sent this worker its work, not
-        // "the primary". With two leads orchestrating one fleet the singular question has no right
-        // answer, and answering it anyway interrupted whichever lead happened to call bridge_send
-        // first with results it never asked for.
-        var nudgeTarget = primaryRegistry.nudgeTargetFor(target);
-        if (nudgeTarget.isEmpty()) {
-            log.debug("push: no lead is known to be waiting on {}, stopping reminder", target);
-            return Action.STOP;
-        }
-        if (inbox.peek(target).isEmpty()) {
-            log.debug("push: inbox empty for {}, stopping reminder", target);
-            return Action.STOP;
-        }
-        if (reminderCount >= maxReminders) {
-            log.debug("push: reminder cap ({}) reached for {}, stopping", maxReminders, target);
-            countNudge("exhausted");
-            return Action.STOP;
-        }
-        String leadTerminal = nudgeTarget.get();
-        AgentStatus status;
-        try {
-            status = agents.status(leadTerminal);
-        } catch (RuntimeException e) {
-            log.debug("push: status check failed for lead {}, will retry", leadTerminal, e);
-            return Action.WAIT_BUSY;
-        }
-        if (status.injectable()) {
-            return Action.INJECT;
-        }
-        log.debug("push: lead {} is {} (not injectable), waiting", leadTerminal, status);
-        return Action.WAIT_BUSY;
-    }
-
-    // --- public entrypoint ---------------------------------------------------------------------
-
-    /**
-     * Called when a reply is queued for {@code target}. Idempotent per target: a second call while
-     * a schedule is active is a no-op. The schedule nudges the primary, then schedules a follow-up
-     * check (reminder on backoff, or re-check on WAIT_BUSY), until the inbox is empty or the cap
-     * is reached.
-     */
-    public void onReplyQueued(String target) {
-        if (activeTargets.putIfAbsent(target, Boolean.TRUE) != null) {
-            log.debug("push: already active for {}, ignoring duplicate trigger", target);
-            return; // already scheduled
-        }
-        log.debug("push: starting reminder loop for {}", target);
-        scheduleNext(target, 0);
-    }
-
-    /** Execute one loop tick — called on the scheduler thread. */
-    private void tick(String target, int reminderCount) {
-        var action = decide(target, reminderCount);
-        switch (action) {
-            case INJECT -> {
-                injectNudge(target, reminderCount);
-                scheduleNext(target, reminderCount + 1);
-            }
-            // Re-check after the configured backoff; the primary may become injectable soon.
-            case WAIT_BUSY -> scheduleNext(target, reminderCount);
-            case STOP -> {
-                activeTargets.remove(target);
-                log.debug("push: reminder loop ended for {}", target);
+    private Set<String> pendingReplyTargetsFor(String lead) {
+        Set<String> result = new HashSet<>();
+        for (var entry : pendingReplies.entrySet()) {
+            String target = entry.getKey();
+            String owningLead = entry.getValue();
+            if (!lead.equals(owningLead)) continue;
+            if (inbox.peek(target).isEmpty()) {
+                pendingReplies.remove(target, owningLead);
+                continue;
             }
+            result.add(target);
         }
+        return result;
     }
 
-    /** Send the nudge and log the event. */
-    private void injectNudge(String target, int reminderCount) {
-        // Re-read rather than threading it down from decide(): the delegating lead can change
-        // between the decision and the injection, and the nudge should follow the current one.
-        var lead = primaryRegistry.nudgeTargetFor(target);
-        if (lead.isEmpty()) {
-            log.debug("push: lead for {} disappeared before the nudge could be sent", target);
-            return;
-        }
-        String leadTerminal = lead.get();
-        String nudge = NUDGE_FORMAT.formatted(target, target);
-        try {
-            agents.send(leadTerminal, nudge);
-            log.debug("push: nudge {}/{} sent to lead {} for target {}",
-                    reminderCount + 1, maxReminders, leadTerminal, target);
-            countNudge("delivered");
-        } catch (RuntimeException e) {
-            log.warn("push: failed to nudge lead {} for target {} (reminder {}/{}): {}",
-                    leadTerminal, target, reminderCount + 1, maxReminders, e.toString());
-        }
-    }
-
-    /** Schedule the next tick on the scheduler thread pool. */
-    private void scheduleNext(String target, int nextReminderCount) {
-        scheduler.schedule(() -> tick(target, nextReminderCount), backoffMs, TimeUnit.MILLISECONDS);
-    }
-
-    // --- CB-588: async ticket terminal nudges ---------------------------------------------------
-
     /** A ticket awaiting collection: which lead to nudge, and whether it ended in failure. */
     private record PendingTicket(String ticket, String lead, boolean failed) {
     }
 
-    /**
-     * Called when an async delegation ticket ({@code bridge_send(wait:false)}, CB-107) reaches a
-     * terminal phase — DONE or a failure. Unlike {@link #onReplyQueued}, which nudges about the
-     * durable-inbox no-waiter path, this covers the path {@code MessageService.reply} takes when a
-     * fire-and-poll send's own rendezvous waiter resolves the reply directly: that path returns
-     * before {@link #onReplyQueued} is ever called, so without this entry point a ticket finishing
-     * that way never nudged anyone (CB-588 / gitea #72).
-     *
-     * <p>Idempotent per lead: several tickets going terminal for the same lead while its schedule is
-     * already active coalesce onto that schedule's next tick rather than firing a nudge each.
-     *
-     * @param ticket the ticket to nudge about
-     * @param target the worker session the ticket was sent to — resolves which lead delegated it
-     * @param failed whether the ticket ended in a failure phase rather than {@code DONE}
-     */
-    public void onTicketTerminal(String ticket, String target, boolean failed) {
-        var lead = primaryRegistry.nudgeTargetFor(target);
-        if (lead.isEmpty()) {
-            log.debug("push: no lead is known to be waiting on ticket {} (target {}), skipping nudge",
-                    ticket, target);
-            return;
-        }
-        pendingTickets.put(ticket, new PendingTicket(ticket, lead.get(), failed));
-        if (activeLeads.putIfAbsent(lead.get(), Boolean.TRUE) != null) {
-            log.debug("push: ticket reminder loop already active for lead {}, {} coalesced in",
-                    lead.get(), ticket);
-            return;
-        }
-        log.debug("push: starting ticket reminder loop for lead {}", lead.get());
-        scheduleTicketTick(lead.get(), 0);
-    }
-
-    /**
-     * Called when a ticket's terminal state has been collected via {@code bridge_poll}. Removes it
-     * from the pending set so a scheduled tick — and any nudge it sends — never names a ticket the
-     * lead already has (CB-588 acceptance #5). A ticket that was never pending (unknown ticket, or
-     * one nudged with no push loop configured) is a no-op.
-     */
-    public void ticketCollected(String ticket) {
-        pendingTickets.remove(ticket);
-    }
-
     /** Tickets still pending for {@code lead}, snapshotted fresh for one tick. */
-    private List<PendingTicket> pendingFor(String lead) {
+    private List<PendingTicket> pendingTicketsFor(String lead) {
         return pendingTickets.values().stream().filter(t -> lead.equals(t.lead())).toList();
     }
 
+    /** Ticket ids still pending for {@code lead} — a plain snapshot for race comparison. */
+    private Set<String> pendingTicketIdsFor(String lead) {
+        return pendingTicketsFor(lead).stream().map(PendingTicket::ticket)
+                .collect(Collectors.toUnmodifiableSet());
+    }
+
     /**
-     * Pure decision function for ticket nudges, mirroring {@link #decide(String, int)} but keyed by
-     * the nudge-receiving lead terminal rather than the worker session — several tickets from
-     * different workers delegated by the same lead coalesce onto it.
+     * Pure decision function: examine everything pending for {@code lead} — reply targets and
+     * tickets alike — and return what the loop should do.
+     *
+     * <p><strong>CB-590-fix: one schedule, two budgets.</strong> The single per-lead schedule
+     * (CB-590) still ticks once for both sources, but each source is capped independently —
+     * {@code replyReminderCount} against a reply target still pending, {@code ticketReminderCount}
+     * against a ticket still pending. A busy reply stream that exhausts its own cap must not stop
+     * the loop from nudging about a ticket that still has budget left, and vice versa: either
+     * source being eligible (has pending work AND is under its own cap) is enough for
+     * {@link Action#INJECT}. Only when neither source has eligible work does the loop
+     * {@link Action#STOP}.
+     *
+     * @param lead                the lead terminal to nudge
+     * @param replyReminderCount  how many nudges have covered pending reply work for this lead
+     * @param ticketReminderCount how many nudges have covered pending ticket work for this lead
+     * @return the action the caller should take
      */
-    Action decideTickets(String lead, int reminderCount) {
-        if (pendingFor(lead).isEmpty()) {
-            log.debug("push: nothing pending for lead {}, stopping ticket reminder", lead);
+    Action decide(String lead, int replyReminderCount, int ticketReminderCount) {
+        boolean hasReplyWork = !pendingReplyTargetsFor(lead).isEmpty();
+        boolean hasTicketWork = !pendingTicketIdsFor(lead).isEmpty();
+        if (!hasReplyWork && !hasTicketWork) {
+            log.debug("push: nothing pending for lead {}, stopping reminder", lead);
             return Action.STOP;
         }
-        if (reminderCount >= maxReminders) {
-            log.debug("push: ticket reminder cap ({}) reached for lead {}, stopping", maxReminders, lead);
+        boolean replyEligible = hasReplyWork && replyReminderCount < maxReminders;
+        boolean ticketEligible = hasTicketWork && ticketReminderCount < maxReminders;
+        if (!replyEligible && !ticketEligible) {
+            log.debug("push: reminder cap ({}) reached for lead {} on every source with pending work, stopping",
+                    maxReminders, lead);
             countNudge("exhausted");
             return Action.STOP;
         }
@@ -278,95 +189,194 @@ public final class ReplyPushLoop {
         return Action.WAIT_BUSY;
     }
 
-    /** Execute one ticket-loop tick — called on the scheduler thread. */
-    private void ticketTick(String lead, int reminderCount) {
-        Set<String> pendingBefore = pendingIdsFor(lead);
-        var action = decideTickets(lead, reminderCount);
-        switch (action) {
-            case INJECT -> {
-                injectTicketNudge(lead, reminderCount);
-                scheduleTicketTick(lead, reminderCount + 1);
-            }
-            case WAIT_BUSY -> scheduleTicketTick(lead, reminderCount);
-            case STOP -> stopOrRestartTicketLoop(lead, pendingBefore);
-        }
-    }
+    // --- public entrypoints ----------------------------------------------------------------------
 
-    /** Ticket IDs pending for {@code lead} right now, as a plain snapshot for race comparison. */
-    private Set<String> pendingIdsFor(String lead) {
-        return pendingFor(lead).stream().map(PendingTicket::ticket).collect(Collectors.toUnmodifiableSet());
+    /**
+     * Called when a reply is queued for {@code target}. Resolves the lead delegating to
+     * {@code target} (CB-532) and coalesces onto that lead's single reminder schedule — starting
+     * one if none is active, joining an already-active one otherwise. A no-op if no lead is known
+     * to be waiting on {@code target}: there is nobody to nudge yet, and the durable inbox is the
+     * backstop until a lead is recorded.
+     */
+    public void onReplyQueued(String target) {
+        var lead = primaryRegistry.nudgeTargetFor(target);
+        if (lead.isEmpty()) {
+            log.debug("push: no lead is known to be waiting on {}, skipping reminder", target);
+            return;
+        }
+        pendingReplies.put(target, lead.get());
+        startOrCoalesce(lead.get());
     }
 
     /**
-     * Release {@code lead}'s active-schedule slot, then restart it only if a ticket landed that
-     * {@code pendingBefore} — the snapshot taken just before this tick's decision — did not already
-     * account for. {@code onTicketTerminal} reads {@code activeLeads} to decide whether to coalesce
-     * onto an existing schedule or start one, so a ticket that lands between {@code decideTickets}
-     * returning {@link Action#STOP} and this removal running sees the (soon-to-be-stale) slot as
-     * occupied, coalesces onto a schedule that is about to die, and gets no nudge scheduled at all —
-     * a lost nudge, the exact failure CB-588 exists to remove (found in review, gitea PR #73).
+     * Called when an async delegation ticket ({@code bridge_send(wait:false)}, CB-107) reaches a
+     * terminal phase — DONE or a failure. Unlike {@link #onReplyQueued}, which nudges about the
+     * durable-inbox no-waiter path, this covers the path {@code MessageService.reply} takes when a
+     * fire-and-poll send's own rendezvous waiter resolves the reply directly: that path returns
+     * before {@link #onReplyQueued} is ever called, so without this entry point a ticket finishing
+     * that way never nudged anyone (CB-588 / gitea #72).
      *
-     * <p>Restarting on ANY non-empty {@code pendingFor(lead)} would be wrong: when STOP is reached
-     * because the reminder cap was hit rather than the backlog draining, the same never-collected
-     * ticket is expected to still be sitting there — that is the cap doing its job — and restarting
-     * would nudge about it forever, defeating the bound (the original CB-307 bounded-reminder
-     * guarantee, carried into CB-588 by acceptance criterion #7 — this exact regression showed up as
-     * two existing tests failing once a naive "any pending ticket restarts" version of this fix went
-     * in: {@code successfulTicketNudgeIncrementsDelivered} and {@code ticketNudgesSendUpToCapThenStop}).
-     * Diffing the current pending set against {@code pendingBefore} tells the two cases apart: a
-     * ticket present before this tick's decision is stale backlog, not a race; only a ticket absent
-     * from {@code pendingBefore} can only have arrived during the decision-to-release window, which is
-     * exactly the race this method closes.
+     * <p>Resolves the delegating lead the same way {@link #onReplyQueued} does and coalesces onto
+     * the same per-lead schedule (CB-590) — several tickets, or a ticket and a reply, finishing
+     * for the same lead while its schedule is already active all ride the existing schedule's next
+     * tick rather than firing a nudge each.
+     *
+     * @param ticket the ticket to nudge about
+     * @param target the worker session the ticket was sent to — resolves which lead delegated it
+     * @param failed whether the ticket ended in a failure phase rather than {@code DONE}
+     */
+    public void onTicketTerminal(String ticket, String target, boolean failed) {
+        var lead = primaryRegistry.nudgeTargetFor(target);
+        if (lead.isEmpty()) {
+            log.debug("push: no lead is known to be waiting on ticket {} (target {}), skipping nudge",
+                    ticket, target);
+            return;
+        }
+        pendingTickets.put(ticket, new PendingTicket(ticket, lead.get(), failed));
+        startOrCoalesce(lead.get());
+    }
+
+    /**
+     * Called when a ticket's terminal state has been collected via {@code bridge_poll}. Removes it
+     * from the pending set so a scheduled tick — and any nudge it sends — never names a ticket the
+     * lead already has. A ticket that was never pending (unknown ticket, or one nudged with no push
+     * loop configured) is a no-op.
+     */
+    public void ticketCollected(String ticket) {
+        pendingTickets.remove(ticket);
+    }
+
+    // --- the schedule ----------------------------------------------------------------------------
+
+    /** Start a reminder schedule for {@code lead}, or join the one already running. */
+    private void startOrCoalesce(String lead) {
+        if (activeLeads.putIfAbsent(lead, Boolean.TRUE) != null) {
+            log.debug("push: reminder loop already active for lead {}, work coalesced in", lead);
+            return;
+        }
+        log.debug("push: starting reminder loop for lead {}", lead);
+        scheduleNext(lead, 0, 0);
+    }
+
+    /** Execute one loop tick — called on the scheduler thread. */
+    private void tick(String lead, int replyReminderCount, int ticketReminderCount) {
+        Set<String> repliesBefore = pendingReplyTargetsFor(lead);
+        Set<String> ticketsBefore = pendingTicketIdsFor(lead);
+        var action = decide(lead, replyReminderCount, ticketReminderCount);
+        switch (action) {
+            case INJECT -> {
+                injectNudge(lead, replyReminderCount, ticketReminderCount);
+                // Only the source(s) actually eligible this tick spend a unit of their own budget —
+                // an exhausted source riding along in the combined message (still pending, still
+                // named) does not get charged again; its count stays put until it drains.
+                boolean replyEligible = !repliesBefore.isEmpty() && replyReminderCount < maxReminders;
+                boolean ticketEligible = !ticketsBefore.isEmpty() && ticketReminderCount < maxReminders;
+                scheduleNext(lead,
+                        replyEligible ? replyReminderCount + 1 : replyReminderCount,
+                        ticketEligible ? ticketReminderCount + 1 : ticketReminderCount);
+            }
+            // Re-check after the configured backoff; the lead may become injectable soon.
+            case WAIT_BUSY -> scheduleNext(lead, replyReminderCount, ticketReminderCount);
+            case STOP -> stopOrRestart(lead, repliesBefore, ticketsBefore);
+        }
+    }
+
+    /**
+     * Release {@code lead}'s active-schedule slot, then restart it only if work landed that
+     * {@code repliesBefore} / {@code ticketsBefore} — the snapshots taken just before this tick's
+     * decision — did not already account for. {@link #onReplyQueued} / {@link #onTicketTerminal}
+     * read {@link #activeLeads} to decide whether to coalesce onto an existing schedule or start
+     * one, so work that lands between {@link #decide} returning {@link Action#STOP} and this
+     * removal running sees the (soon-to-be-stale) slot as occupied, coalesces onto a schedule that
+     * is about to die, and gets no nudge scheduled at all — a lost nudge, exactly what CB-588 (and
+     * now CB-590) exist to remove (originally found in review, gitea PR #73, for the ticket-only
+     * loop; carried forward here for the unified one).
+     *
+     * <p>Restarting on ANY non-empty pending set would be wrong: when STOP is reached because the
+     * reminder cap was hit rather than the backlog draining, the same never-collected work is
+     * expected to still be sitting there — that is the cap doing its job — and restarting would
+     * nudge about it forever, defeating the bound. Diffing the current pending sets against the
+     * "before" snapshots tells the two cases apart: an item present before this tick's decision is
+     * stale backlog, not a race; only an item absent from the "before" snapshot can only have
+     * arrived during the decision-to-release window, which is exactly the race this method closes.
      *
      * <p>Package-private so a test can drive the interleaving directly rather than trying to force a
-     * genuine thread race: pass the exact {@code pendingBefore} snapshot a race requires (or does
-     * not) and call this to prove the recheck responds correctly either way.
+     * genuine thread race.
      *
-     * <p>Terminates rather than spinning: this method restarts the schedule at most once per call, and
-     * a fresh {@link #onTicketTerminal} racing the recheck below still terminates in one of two ways —
-     * either it observes the slot already vacated (by the {@code activeLeads.remove} above, which
-     * happens-before this recheck in program order) and claims it itself, or it lands first and this
-     * recheck then observes its ticket in {@code pendingTickets} and reclaims the slot instead. Exactly
-     * one side always wins; neither can miss the other, so this never loops on its own account.
+     * <p>Terminates rather than spinning: this method restarts the schedule at most once per call,
+     * and a fresh {@link #onReplyQueued} / {@link #onTicketTerminal} racing the recheck below still
+     * terminates in one of two ways — either it observes the slot already vacated (by the
+     * {@code activeLeads.remove} above, which happens-before this recheck in program order) and
+     * claims it itself, or it lands first and this recheck then observes its work in
+     * {@link #pendingReplies} / {@link #pendingTickets} and reclaims the slot instead. Exactly one
+     * side always wins; neither can miss the other, so this never loops on its own account.
      */
-    void stopOrRestartTicketLoop(String lead, Set<String> pendingBefore) {
+    void stopOrRestart(String lead, Set<String> repliesBefore, Set<String> ticketsBefore) {
         activeLeads.remove(lead);
-        boolean ticketRacedIn = pendingFor(lead).stream().anyMatch(t -> !pendingBefore.contains(t.ticket()));
-        if (ticketRacedIn && activeLeads.putIfAbsent(lead, Boolean.TRUE) == null) {
-            log.debug("push: a ticket for lead {} raced the reminder loop's stop — restarting", lead);
-            scheduleTicketTick(lead, 0);
+        boolean racedIn = pendingReplyTargetsFor(lead).stream().anyMatch(t -> !repliesBefore.contains(t))
+                || pendingTicketIdsFor(lead).stream().anyMatch(t -> !ticketsBefore.contains(t));
+        if (racedIn && activeLeads.putIfAbsent(lead, Boolean.TRUE) == null) {
+            log.debug("push: new work for lead {} raced the reminder loop's stop — restarting", lead);
+            scheduleNext(lead, 0, 0);
             return;
         }
-        log.debug("push: ticket reminder loop ended for lead {}", lead);
+        log.debug("push: reminder loop ended for lead {}", lead);
     }
 
-    /** Send the coalesced ticket nudge and log the event. */
-    private void injectTicketNudge(String lead, int reminderCount) {
-        // Re-read rather than threading it down from decideTickets(): a ticket can be collected (or
-        // another can arrive) between the decision and the injection.
-        List<PendingTicket> pending = pendingFor(lead);
-        if (pending.isEmpty()) {
-            log.debug("push: pending tickets for lead {} drained before the nudge could be sent", lead);
+    /** Send one combined nudge covering everything currently pending for {@code lead}. */
+    private void injectNudge(String lead, int replyReminderCount, int ticketReminderCount) {
+        // Re-read rather than threading it down from decide(): a reply can drain, or a ticket be
+        // collected (or another arrive), between the decision and the injection.
+        Set<String> replyTargets = pendingReplyTargetsFor(lead);
+        List<PendingTicket> tickets = pendingTicketsFor(lead);
+        if (replyTargets.isEmpty() && tickets.isEmpty()) {
+            log.debug("push: pending work for lead {} drained before the nudge could be sent", lead);
             return;
         }
-        String nudge = formatTicketsNudge(pending);
+        String nudge = formatNudge(replyTargets, tickets);
         try {
             agents.send(lead, nudge);
-            log.debug("push: ticket nudge {}/{} sent to lead {} for {} ticket(s)",
-                    reminderCount + 1, maxReminders, lead, pending.size());
+            log.debug("push: nudge sent to lead {} (reply {}/{}, ticket {}/{}; {} reply target(s), {} ticket(s))",
+                    lead, replyReminderCount + 1, maxReminders, ticketReminderCount + 1, maxReminders,
+                    replyTargets.size(), tickets.size());
             countNudge("delivered");
         } catch (RuntimeException e) {
-            log.warn("push: failed to nudge lead {} for {} ticket(s) (reminder {}/{}): {}",
-                    lead, pending.size(), reminderCount + 1, maxReminders, e.toString());
+            log.warn("push: failed to nudge lead {} (reply {}/{}, ticket {}/{}): {}",
+                    lead, replyReminderCount + 1, maxReminders, ticketReminderCount + 1, maxReminders, e.toString());
         }
     }
 
-    /** Schedule the next ticket-loop tick on the scheduler thread pool. */
-    private void scheduleTicketTick(String lead, int nextReminderCount) {
-        scheduler.schedule(() -> ticketTick(lead, nextReminderCount), backoffMs, TimeUnit.MILLISECONDS);
+    /** Schedule the next tick on the scheduler thread pool. */
+    private void scheduleNext(String lead, int nextReplyReminderCount, int nextTicketReminderCount) {
+        scheduler.schedule(() -> tick(lead, nextReplyReminderCount, nextTicketReminderCount),
+                backoffMs, TimeUnit.MILLISECONDS);
     }
 
-    /** Render one or several pending tickets as a single nudge line. */
+    // --- nudge formatting ------------------------------------------------------------------------
+
+    /** Render everything pending for one lead as a single nudge line. */
+    private static String formatNudge(Set<String> replyTargets, List<PendingTicket> tickets) {
+        List<String> parts = new ArrayList<>();
+        if (!replyTargets.isEmpty()) {
+            parts.add(formatRepliesNudge(replyTargets));
+        }
+        if (!tickets.isEmpty()) {
+            parts.add(formatTicketsNudge(tickets));
+        }
+        return String.join(" | ", parts);
+    }
+
+    /** Render one or several pending reply targets. */
+    private static String formatRepliesNudge(Set<String> targets) {
+        if (targets.size() == 1) {
+            String target = targets.iterator().next();
+            return NUDGE_FORMAT.formatted(target, target);
+        }
+        String ids = String.join(", ", targets);
+        return REPLIES_NUDGE_FORMAT.formatted(targets.size(), ids);
+    }
+
+    /** Render one or several pending tickets. */
     private static String formatTicketsNudge(List<PendingTicket> pending) {
         if (pending.size() == 1) {
             PendingTicket t = pending.get(0);
@@ -383,23 +393,22 @@ public final class ReplyPushLoop {
     // --- lifecycle -----------------------------------------------------------------------------
 
     /**
-     * Whether any reminder loop is currently active for some target (CB-551). The idle-lead heartbeat
-     * uses this to stand aside: while the push loop is actively nudging the lead, a concurrent
-     * heartbeat injection would start a second competing turn in the same pane — racing loops multiply
-     * turns and context burn. "Active" means a schedule exists in {@link #activeTargets} or
-     * {@link #activeLeads} (CB-588 ticket nudges are a second source of pane injections the heartbeat
-     * must equally stand aside for); the sets are bounded by what has been triggered, not by any
-     * persistent state.
+     * Whether any reminder loop is currently active for some lead (CB-551). The idle-lead heartbeat
+     * uses this to stand aside: while the push loop is actively nudging a lead, a concurrent
+     * heartbeat injection would start a second competing turn in the same pane — racing loops
+     * multiply turns and context burn. "Active" means a schedule exists in {@link #activeLeads},
+     * which now covers both reply-queued (CB-307) and ticket-terminal (CB-588) work (CB-590) —
+     * bounded by what has been triggered, not by any persistent state.
      */
     public boolean isActive() {
-        return !activeTargets.isEmpty() || !activeLeads.isEmpty();
+        return !activeLeads.isEmpty();
     }
 
     /** Shut down the scheduler. Outstanding reminders are cancelled. */
     public void stop() {
         scheduler.shutdownNow();
-        activeTargets.clear();
         activeLeads.clear();
+        pendingReplies.clear();
         pendingTickets.clear();
     }
 

bridged/src/main/java/dev/ltms/bridged/rest/BridgedApp.java

@@ -13,6 +13,7 @@ import dev.ltms.bridged.herdr.HerdrClient;
 import dev.ltms.bridged.herdr.HerdrException;
 import dev.ltms.bridged.inject.MemberPresence;
 import dev.ltms.bridged.peer.PeerUnreachableException;
+import dev.ltms.bridged.placement.PlacementException;
 import dev.ltms.bridged.msg.MessageService;
 import dev.ltms.bridged.session.SessionManager;
 import dev.ltms.bridged.peer.MemberRole;
@@ -292,6 +293,11 @@ public final class BridgedApp {
             ctx.status(201).json(view(member));
         } catch (GuardException e) {
             ctx.status(403).json(Map.of("error", "subscription_boundary", "detail", e.getMessage()));
+        } catch (PlacementException e) {
+            // CB-599: no candidate had capacity (maxLoad, quarantine, or all-exhausted) — a benign,
+            // likely-transient refusal, distinct from "profile does not exist" below. 503: the
+            // request was valid and will likely succeed later.
+            ctx.status(503).json(Map.of("error", "no_capacity", "detail", e.getMessage()));
         } catch (IllegalArgumentException e) {
             ctx.status(400).json(Map.of("error", "unknown_profile", "detail", e.getMessage()));
         } catch (PeerUnreachableException e) {

bridged/src/test/java/dev/ltms/bridged/mcp/BridgeMcpTest.java

@@ -16,12 +16,15 @@ import dev.ltms.bridged.inject.MemberPresence;
 import dev.ltms.bridged.session.MemberSession;
 import dev.ltms.bridged.session.WorktreeRequest;
 import dev.ltms.bridged.member.ClaudeCodeLauncher;
+import dev.ltms.bridged.member.CompositePeerLauncher;
 import dev.ltms.bridged.placement.BackendQuarantine;
+import dev.ltms.bridged.placement.PlacementPolicies;
 import io.modelcontextprotocol.spec.McpSchema;
 import dev.ltms.bridged.msg.InMemoryReplyInbox;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
@@ -423,6 +426,35 @@ class BridgeMcpTest {
         assertTrue(textOf(res).contains("unknown worker profile"), textOf(res));
     }
 
+    /**
+     * CB-599: a profile at its {@code maxLoad} cap must surface a readable reason on the MCP
+     * surface too, not merely flip {@code isError} with an opaque or absent message.
+     */
+    @Test
+    void spawnAtMaxLoadSurfacesTheCapacityReason() {
+        FakeHerdr h = new FakeHerdr();
+        BridgedConfig.Profile wcfg = new BridgedConfig.Profile(
+                "ltms-local", "http://gx00.gw:8000", "coder", null, "BRIDGED_WORKER_TOKEN", null,
+                "tab", "bridged-workers", "worker: {profile} #{n}", null,
+                null, null, null, null, null, null, null, 0, null, null, null);
+        Map<String, BridgedConfig.Profile> profiles = Map.of(wcfg.profile(), wcfg);
+        ClaudeCodeLauncher delegate = new ClaudeCodeLauncher(
+                new AgentControl(h), new WorkspaceControl(h), new SubscriptionGuard(Set.of("gx00.gw")),
+                profiles, wcfg.profile(), k -> "BRIDGED_WORKER_TOKEN".equals(k) ? "tok" : null);
+        CompositePeerLauncher composite = new CompositePeerLauncher(
+                List.of(delegate), wcfg.profile(), profiles, PlacementPolicies.fixed(), _ -> 0);
+        SessionManager sm = new SessionManager(composite);
+
+        McpSchema.CallToolResult res = BridgeMcp.spawn(sm, "ltms-local");
+
+        assertTrue(res.isError());
+        String text = textOf(res);
+        assertTrue(text.contains("no capacity"), "surfaces a capacity reason, not a bare error: " + text);
+        assertTrue(text.contains("ltms-local"), "names the profile: " + text);
+        assertTrue(text.contains("maxLoad"), "explains the refusal: " + text);
+        assertFalse(h.called("agent.start"), "at cap, the spawn is refused before any herdr call");
+    }
+
     @Test
     void spawnPassesTheRequestedCwdToTheWorker() {
         FakeHerdr h = new FakeHerdr();

bridged/src/test/java/dev/ltms/bridged/msg/AmqpReplyInboxContractTest.java

@@ -16,6 +16,7 @@ import java.util.List;
 import java.util.concurrent.TimeUnit;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
@@ -166,6 +167,88 @@ class AmqpReplyInboxContractTest {
         }
     }
 
+    @Test
+    void prefetchBoundsTheHeldBacklog() throws Exception {
+        String target = "worker-prefetch-" + System.nanoTime();
+        int prefetch = 4;
+        int published = 10;
+        try (AmqpReplyInbox inbox = new AmqpReplyInbox(newConnection(), prefetch);
+             Connection inspect = newConnection()) {
+            inbox.own(target);
+            for (int i = 0; i < published; i++) {
+                inbox.publish(target, "m" + i, "payload " + i);
+            }
+            awaitHeldAtLeast(inbox, target, prefetch);
+
+            long depth;
+            try (Channel ch = inspect.createChannel()) {
+                depth = ch.queueDeclarePassive(queueName(target)).getMessageCount();
+            }
+            assertTrue(depth >= published - prefetch,
+                    "broker should still hold at least " + (published - prefetch)
+                            + " undelivered messages behind a prefetch of " + prefetch + ", saw " + depth);
+
+            drainUntilEmpty(inbox, target, inspect);
+        }
+    }
+
+    @Test
+    void unroutablePublishReportsFailureNotSilentSuccess() throws Exception {
+        String target = "worker-unroutable-" + System.nanoTime();
+        try (AmqpReplyInbox inbox = AmqpReplyInbox.open(uri())) {
+            // Deliberately never own(target): the queue is never declared, so the default-exchange
+            // route to agent.<target>.inbox does not exist and the broker must return the publish.
+            IllegalStateException ex = assertThrows(IllegalStateException.class,
+                    () -> inbox.publish(target, "m1", "nobody home"));
+            assertTrue(ex.getMessage() != null && ex.getMessage().toLowerCase().contains("unroutable"),
+                    "expected an unroutable-publish failure, got: " + ex.getMessage());
+        }
+    }
+
+    @Test
+    void confirmedPublishDeliversNormally() throws Exception {
+        String target = "worker-confirm-" + System.nanoTime();
+        try (AmqpReplyInbox inbox = AmqpReplyInbox.open(uri())) {
+            inbox.own(target);
+            inbox.publish(target, "m1", "confirmed delivery"); // must return normally: routed and confirmed
+
+            List<ReplyInbox.InboxMessage> got = awaitPeek(inbox, target);
+            assertEquals(1, got.size());
+            assertEquals("confirmed delivery", got.getFirst().content());
+            inbox.ack(target, "m1");
+        }
+    }
+
+    /** Poll peek until at least {@code n} replies for {@code target} are held, or ~10s elapse. */
+    @SuppressWarnings("BusyWait")
+    private static void awaitHeldAtLeast(AmqpReplyInbox inbox, String target, int n) throws InterruptedException {
+        long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(10);
+        while (inbox.peek(target).size() < n && System.nanoTime() < deadline) {
+            Thread.sleep(50);
+        }
+    }
+
+    /**
+     * Repeatedly ack whatever is currently held (freeing prefetch slots for the next delivery) until
+     * both the local snapshot and the broker's own queue depth are empty, or ~10s elapse.
+     */
+    @SuppressWarnings("BusyWait")
+    private static void drainUntilEmpty(AmqpReplyInbox inbox, String target, Connection inspect) throws Exception {
+        long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(10);
+        while (System.nanoTime() < deadline) {
+            for (ReplyInbox.InboxMessage msg : inbox.peek(target)) {
+                inbox.ack(target, msg.msgId());
+            }
+            try (Channel ch = inspect.createChannel()) {
+                if (ch.queueDeclarePassive(queueName(target)).getMessageCount() == 0 && inbox.peek(target).isEmpty()) {
+                    return;
+                }
+            }
+            Thread.sleep(50);
+        }
+        throw new AssertionError("did not drain " + target + " to empty within the deadline");
+    }
+
     /** Poll peek (broker delivery is async) until a reply for {@code target} appears or ~10s elapse. */
     @SuppressWarnings("BusyWait") // deliberate poll for async broker delivery, bounded by the deadline
     private static List<ReplyInbox.InboxMessage> awaitPeek(AmqpReplyInbox inbox, String target)

bridged/src/test/java/dev/ltms/bridged/msg/AmqpReplyInboxRecoveryRaceTest.java

@@ -0,0 +1,264 @@
+package dev.ltms.bridged.msg;
+
+import com.rabbitmq.client.AMQP;
+import com.rabbitmq.client.Channel;
+import com.rabbitmq.client.ConfirmCallback;
+import com.rabbitmq.client.Connection;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Proxy;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * CB-528 follow-up: {@link AmqpReplyInbox#failPendingPublishesOnRecovery()} must not fail a publish
+ * that registers concurrently with (and was not yet visible when) the recovery sweep began — that
+ * would report a publish that actually succeeded as failed, and {@code MessageService.reply} retries
+ * with a fresh {@code msgId}, so the reply is delivered twice. A live broker reconnect cannot be
+ * forced reliably, so this drives {@link AmqpReplyInbox#failPendingPublishesOnRecovery} and a real
+ * {@link AmqpReplyInbox#publish} against each other directly, against fake AMQP channels built with
+ * {@link Proxy} (no mocking library is on the classpath).
+ *
+ * <p>Also covers Finding 2 (CB-528 follow-up): {@link AmqpReplyInbox#close()} must fail an in-flight
+ * publish promptly instead of leaving it to idle out the 10s confirm timeout.
+ */
+class AmqpReplyInboxRecoveryRaceTest {
+
+    /** Large enough that the (unfixed) unsynchronized sweep's iteration is a real, observable window
+     *  a concurrently-started publish can land in — not just a best case, single-entry sprint. */
+    private static final int STALE_PUBLISHES = 100_000;
+
+    @Test
+    @Timeout(30)
+    void recoverySweepDoesNotFailAPublishThatRegistersWhileItIsRunning() throws Exception {
+        AtomicLong seqCounter = new AtomicLong();
+        List<Long> seqOrder = new CopyOnWriteArrayList<>();
+        List<String> msgIdOrder = new CopyOnWriteArrayList<>();
+        AtomicReference<ConfirmCallback> ackCallback = new AtomicReference<>();
+        AtomicReference<ConfirmCallback> nackCallback = new AtomicReference<>();
+
+        Channel publishChannel = fakeChannel(seqCounter, seqOrder, msgIdOrder, ackCallback, nackCallback);
+        Channel consumeChannel = fakeChannel(seqCounter, seqOrder, msgIdOrder, ackCallback, nackCallback);
+        Connection connection = fakeConnection(consumeChannel, publishChannel);
+
+        AmqpReplyInbox inbox = new AmqpReplyInbox(connection, AmqpReplyInbox.DEFAULT_PREFETCH);
+
+        // STALE_PUBLISHES in-flight publishes that never get confirmed — they sit in pendingBySeq /
+        // pendingByMsgId exactly like publishes whose confirm never arrived before a connection drop.
+        // Virtual threads make this many concurrent blocking publish() calls cheap.
+        CountDownLatch staleStarted = new CountDownLatch(STALE_PUBLISHES);
+        for (int i = 0; i < STALE_PUBLISHES; i++) {
+            String msgId = "stale-" + i;
+            Thread.ofVirtual().start(() -> {
+                staleStarted.countDown();
+                try {
+                    inbox.publish("worker-stale", msgId, "x");
+                } catch (IllegalStateException expected) {
+                    // resolved (failed by the sweep) — that is exactly what this thread is here for
+                }
+            });
+        }
+        staleStarted.await();
+        // Let the registrations (the synchronized put into pendingBySeq/pendingByMsgId) actually land
+        // for all of them before the sweep starts, so the sweep begins with a large, real backlog.
+        Thread.sleep(300);
+
+        AtomicReference<Throwable> sweepError = new AtomicReference<>();
+        Thread sweepThread = new Thread(() -> {
+            try {
+                inbox.failPendingPublishesOnRecovery();
+            } catch (Throwable t) {
+                sweepError.set(t);
+            }
+        }, "recovery-sweep");
+        sweepThread.start();
+        // A short, deliberate head start: with STALE_PUBLISHES this large, the (unfixed) sweep's own
+        // iteration takes several milliseconds, so this guarantees the sweep has already begun —
+        // and, once guarded, is already holding publishChannelLock — before "fresh" attempts to
+        // register. Without this head start, "fresh" sometimes wins the race for the lock and
+        // registers before the sweep even starts, which is the accepted "already in flight when
+        // recovery fires" case (correctly failed either way) rather than the bug under test.
+        Thread.sleep(5);
+
+        // This is the exact interleaving CB-528's follow-up describes: "the still-running recovery
+        // sweep" racing a publish that registers while it is mid-flight.
+        AtomicReference<Throwable> publishError = new AtomicReference<>();
+        Thread freshThread = new Thread(() -> {
+            try {
+                inbox.publish("worker-fresh", "fresh", "hello");
+            } catch (Throwable t) {
+                publishError.set(t);
+            }
+        }, "fresh-publish");
+        freshThread.start();
+
+        sweepThread.join(20_000);
+        assertNull(sweepError.get(), "sweep threw: " + sweepError.get());
+
+        // Simulate the broker's real confirm for "fresh" now that the sweep is done, so a correct
+        // implementation's publish() returns normally instead of idling out CONFIRM_TIMEOUT_MS. Poll
+        // for the registration rather than checking once: freshThread may still be contending for
+        // publishChannelLock (behind the 20,000 stale threads' own lock acquisitions) even though the
+        // sweep itself has already finished.
+        long deadline = System.nanoTime() + TimeUnit.SECONDS.toNanos(9);
+        int idx = -1;
+        while (idx < 0 && System.nanoTime() < deadline) {
+            idx = msgIdOrder.indexOf("fresh");
+            if (idx < 0) {
+                Thread.sleep(20);
+            }
+        }
+        if (idx >= 0 && ackCallback.get() != null) {
+            ackCallback.get().handle(seqOrder.get(idx), false);
+        }
+        freshThread.join(15_000);
+
+        assertNull(publishError.get(),
+                "a publish that registered while the recovery sweep was running must not be failed by "
+                        + "it, but got: " + publishError.get());
+    }
+
+    @Test
+    @Timeout(15)
+    void closeFailsInFlightPublishPromptlyInsteadOfWaitingOutTheConfirmTimeout() throws Exception {
+        AtomicLong seqCounter = new AtomicLong();
+        List<Long> seqOrder = new CopyOnWriteArrayList<>();
+        List<String> msgIdOrder = new CopyOnWriteArrayList<>();
+        AtomicReference<ConfirmCallback> ackCallback = new AtomicReference<>();
+        AtomicReference<ConfirmCallback> nackCallback = new AtomicReference<>();
+
+        Channel publishChannel = fakeChannel(seqCounter, seqOrder, msgIdOrder, ackCallback, nackCallback);
+        Channel consumeChannel = fakeChannel(seqCounter, seqOrder, msgIdOrder, ackCallback, nackCallback);
+        Connection connection = fakeConnection(consumeChannel, publishChannel);
+
+        AmqpReplyInbox inbox = new AmqpReplyInbox(connection, AmqpReplyInbox.DEFAULT_PREFETCH);
+
+        CountDownLatch publishReturned = new CountDownLatch(1);
+        AtomicReference<Throwable> publishError = new AtomicReference<>();
+        AtomicLong elapsedMillis = new AtomicLong();
+        Thread publishThread = new Thread(() -> {
+            long start = System.nanoTime();
+            try {
+                inbox.publish("worker-close", "never-confirmed", "x");
+            } catch (Throwable t) {
+                publishError.set(t);
+            } finally {
+                elapsedMillis.set((System.nanoTime() - start) / 1_000_000);
+                publishReturned.countDown();
+            }
+        }, "publish-during-close");
+        publishThread.start();
+
+        Thread.sleep(200); // let publish() register before close() runs
+        inbox.close();
+
+        assertTrue(publishReturned.await(5, TimeUnit.SECONDS), "publish() did not return after close()");
+        assertNotNull(publishError.get(), "a publish in flight when close() runs must fail, not hang");
+        assertTrue(publishError.get().getMessage() != null
+                        && publishError.get().getMessage().toLowerCase().contains("closed"),
+                "expected a clear closed-inbox message, got: " + publishError.get());
+        assertTrue(elapsedMillis.get() < 5_000,
+                "close() should fail the in-flight publish promptly, not wait out the confirm timeout — took "
+                        + elapsedMillis.get() + "ms");
+    }
+
+    /** A {@link Proxy}-backed {@link Channel}: only the calls {@link AmqpReplyInbox} actually makes
+     *  are meaningfully implemented; everything else returns a harmless default. */
+    private static Channel fakeChannel(AtomicLong seqCounter, List<Long> seqOrder, List<String> msgIdOrder,
+                                        AtomicReference<ConfirmCallback> ackCallback,
+                                        AtomicReference<ConfirmCallback> nackCallback) {
+        InvocationHandler handler = (proxy, method, args) -> {
+            String name = method.getName();
+            if (name.equals("getNextPublishSeqNo")) {
+                long value = seqCounter.incrementAndGet();
+                seqOrder.add(value);
+                return value;
+            }
+            if (name.equals("basicPublish")) {
+                AMQP.BasicProperties props = (AMQP.BasicProperties) args[3];
+                msgIdOrder.add(props.getMessageId());
+                return null;
+            }
+            if (name.equals("addConfirmListener")) {
+                ackCallback.set((ConfirmCallback) args[0]);
+                nackCallback.set((ConfirmCallback) args[1]);
+                return null;
+            }
+            if (name.equals("equals")) {
+                return proxy == args[0];
+            }
+            if (name.equals("hashCode")) {
+                return System.identityHashCode(proxy);
+            }
+            if (name.equals("toString")) {
+                return "FakeChannel";
+            }
+            return defaultValue(method.getReturnType());
+        };
+        return (Channel) Proxy.newProxyInstance(AmqpReplyInboxRecoveryRaceTest.class.getClassLoader(),
+                new Class<?>[] {Channel.class}, handler);
+    }
+
+    /** A {@link Proxy}-backed {@link Connection} handing out {@code first} then {@code second} from
+     *  successive {@code createChannel()} calls, matching {@link AmqpReplyInbox}'s constructor. */
+    private static Connection fakeConnection(Channel first, Channel second) {
+        AtomicInteger calls = new AtomicInteger();
+        InvocationHandler handler = (proxy, method, args) -> {
+            String name = method.getName();
+            if (name.equals("createChannel") && (args == null || args.length == 0)) {
+                return calls.getAndIncrement() == 0 ? first : second;
+            }
+            if (name.equals("equals")) {
+                return proxy == args[0];
+            }
+            if (name.equals("hashCode")) {
+                return System.identityHashCode(proxy);
+            }
+            if (name.equals("toString")) {
+                return "FakeConnection";
+            }
+            return defaultValue(method.getReturnType());
+        };
+        return (Connection) Proxy.newProxyInstance(AmqpReplyInboxRecoveryRaceTest.class.getClassLoader(),
+                new Class<?>[] {Connection.class}, handler);
+    }
+
+    private static Object defaultValue(Class<?> type) {
+        if (!type.isPrimitive() || type == void.class) {
+            return null;
+        }
+        if (type == boolean.class) {
+            return Boolean.FALSE;
+        }
+        if (type == long.class) {
+            return 0L;
+        }
+        if (type == short.class) {
+            return (short) 0;
+        }
+        if (type == byte.class) {
+            return (byte) 0;
+        }
+        if (type == char.class) {
+            return (char) 0;
+        }
+        if (type == double.class) {
+            return 0.0d;
+        }
+        if (type == float.class) {
+            return 0.0f;
+        }
+        return 0;
+    }
+}

bridged/src/test/java/dev/ltms/bridged/msg/ReplyPushLoopTest.java

@@ -20,6 +20,7 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import static org.junit.jupiter.api.Assertions.*;
 
@@ -27,6 +28,12 @@ import static org.junit.jupiter.api.Assertions.*;
  * Unit tests for {@link ReplyPushLoop}: decision logic, nudge injection, idempotency,
  * bounded reminders, and stop conditions.
  *
+ * <p>CB-590 collapsed the CB-307 reply-nudge schedule and the CB-588 ticket-nudge schedule into
+ * one schedule per lead ({@link ReplyPushLoop#decide}), so most tests below register pending work
+ * through the public entry points ({@code onReplyQueued} / {@code onTicketTerminal}) before
+ * exercising {@code decide} directly, mirroring how the two entry points now share one decision
+ * function keyed by the lead terminal rather than by worker target.
+ *
  * <p>Uses a {@link RecordingHerdrClient} that synchronizes access to its call list so the
  * scheduler thread and test thread never have memory ordering issues. The {@code decide()}
  * tests use a simple client with no concurrency concern.
@@ -58,38 +65,50 @@ class ReplyPushLoopTest {
     // --- decide() logic ------------------------------------------------------------------------
 
     @Test
-    void decideWithoutPrimaryIsStop() {
-        agents = agentWithStatus("idle");
-        var loop = new ReplyPushLoop(
-                new PrimaryRegistry(null), agents, inbox, scheduler, 5, 100);
-        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(WORKER, 0));
+    void onReplyQueuedWithNoKnownLeadNeverStartsASchedule() throws Exception {
+        var rec = recordingClient();
+        agents = new AgentControl(rec);
+        inbox.publish(WORKER, "m1", "hello");
+        var loop = new ReplyPushLoop(new PrimaryRegistry(null), agents, inbox, scheduler, 5, 50);
+
+        loop.onReplyQueued(WORKER); // no lead known -> never registered, never scheduled
+
+        assertFalse(loop.isActive(), "no lead known means nothing to nudge yet");
+        Thread.sleep(150);
+        assertEquals(0, rec.sendCount(), "must not nudge when no lead is known to be waiting");
     }
 
     @Test
-    void decideWithEmptyInboxIsStop() {
+    void decideWithNothingPendingIsStop() {
         agents = agentWithStatus("idle");
-        assertEquals(ReplyPushLoop.Action.STOP, loop().decide(WORKER, 0));
+        assertEquals(ReplyPushLoop.Action.STOP, loop().decide(PRIMARY, 0, 0));
     }
 
     @Test
     void decideAtCapIsStop() {
         agents = agentWithStatus("idle");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.STOP, loop(2, 100).decide(WORKER, 2));
+        var loop = loop(2, 100);
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 2, 0));
     }
 
     @Test
     void decideUnderCapWithInjectablePrimaryIsInject() {
         agents = agentWithStatus("idle");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.INJECT, loop().decide(WORKER, 0));
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 0, 0));
     }
 
     @Test
     void decideUnderCapWithBlockedPrimaryIsInject() {
         agents = agentWithStatus("blocked");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.INJECT, loop().decide(WORKER, 0),
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 0, 0),
                 "BLOCKED is injectable");
     }
 
@@ -97,7 +116,9 @@ class ReplyPushLoopTest {
     void decideUnderCapWithDonePrimaryIsInject() {
         agents = agentWithStatus("done");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.INJECT, loop().decide(WORKER, 0),
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 0, 0),
                 "DONE is injectable");
     }
 
@@ -105,23 +126,29 @@ class ReplyPushLoopTest {
     void decideUnderCapWithBusyPrimaryIsWaitBusy() {
         agents = agentWithStatus("working");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop().decide(WORKER, 0));
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop.decide(PRIMARY, 0, 0));
     }
 
     @Test
     void decideUnderCapWithUnknownPrimaryIsWaitBusy() {
         agents = agentWithStatus("unknown");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop().decide(WORKER, 0));
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop.decide(PRIMARY, 0, 0));
     }
 
     @Test
     void decideStopsAfterInboxIsEmptied() {
         agents = agentWithStatus("idle");
         inbox.publish(WORKER, "m1", "hello");
-        assertEquals(ReplyPushLoop.Action.INJECT, loop().decide(WORKER, 0));
+        var loop = loop();
+        loop.onReplyQueued(WORKER);
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 0, 0));
         inbox.ack(WORKER, "m1");
-        assertEquals(ReplyPushLoop.Action.STOP, loop().decide(WORKER, 0));
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 0, 0));
     }
 
     // --- onReplyQueued integration -------------------------------------------------------------
@@ -201,12 +228,19 @@ class ReplyPushLoopTest {
         assertTrue(nudge.contains("bridge_poll(target=term_worker)"));
     }
 
-    // --- CB-588: async ticket terminal nudges — decideTickets() logic --------------------------
+    @Test
+    void repliesNudgeFormatIsCorrect() {
+        String multi = ReplyPushLoop.REPLIES_NUDGE_FORMAT.formatted(2, "term_worker1, term_worker2");
+        assertTrue(multi.contains("2 workers"));
+        assertTrue(multi.contains("bridge_poll(target=...)"));
+    }
+
+    // --- CB-588: async ticket terminal nudges — decide() logic on tickets -----------------------
 
     @Test
     void decideTicketsWithNothingPendingIsStop() {
         agents = agentWithStatus("idle");
-        assertEquals(ReplyPushLoop.Action.STOP, loop().decideTickets(PRIMARY, 0));
+        assertEquals(ReplyPushLoop.Action.STOP, loop().decide(PRIMARY, 0, 0));
     }
 
     @Test
@@ -214,7 +248,7 @@ class ReplyPushLoopTest {
         agents = agentWithStatus("idle");
         var loop = loop(2, 100_000);
         loop.onTicketTerminal("task-1", WORKER, false);
-        assertEquals(ReplyPushLoop.Action.STOP, loop.decideTickets(PRIMARY, 2));
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 0, 2));
     }
 
     @Test
@@ -222,7 +256,7 @@ class ReplyPushLoopTest {
         agents = agentWithStatus("idle");
         var loop = loop(5, 100_000);
         loop.onTicketTerminal("task-1", WORKER, false);
-        assertEquals(ReplyPushLoop.Action.INJECT, loop.decideTickets(PRIMARY, 0));
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 0, 0));
     }
 
     @Test
@@ -230,7 +264,7 @@ class ReplyPushLoopTest {
         agents = agentWithStatus("working");
         var loop = loop(5, 100_000);
         loop.onTicketTerminal("task-1", WORKER, false);
-        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop.decideTickets(PRIMARY, 0));
+        assertEquals(ReplyPushLoop.Action.WAIT_BUSY, loop.decide(PRIMARY, 0, 0));
     }
 
     @Test
@@ -238,7 +272,7 @@ class ReplyPushLoopTest {
         agents = agentWithStatus("idle");
         var loop = new ReplyPushLoop(new PrimaryRegistry(null), agents, inbox, scheduler, 5, 100_000);
         loop.onTicketTerminal("task-1", WORKER, false); // no lead known -> never registered as pending
-        assertEquals(ReplyPushLoop.Action.STOP, loop.decideTickets(PRIMARY, 0));
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 0, 0));
     }
 
     // --- CB-588: onTicketTerminal integration ---------------------------------------------------
@@ -255,7 +289,7 @@ class ReplyPushLoopTest {
         String nudge = rec.sentParams().getFirst().getValue().toString();
         assertTrue(nudge.contains("task-1"), "nudge should name the ticket");
         assertTrue(nudge.contains("bridge_poll(ticket="), "nudge should name the exact ticket-poll call");
-        assertFalse(nudge.contains("bridge_poll(target="), "a ticket nudge must not tell the lead to run the target-poll call");
+        assertFalse(nudge.contains("bridge_poll(target="), "a ticket-only nudge must not tell the lead to run the target-poll call");
     }
 
     @Test
@@ -346,11 +380,11 @@ class ReplyPushLoopTest {
     void aTicketStillPendingWhenTheLoopStopsIsNotStranded() {
         // Regression for the race a reviewer found in gitea PR #73: onTicketTerminal's
         // activeLeads.putIfAbsent can see the lead's slot as still occupied a moment before
-        // decideTickets' STOP releases it, so the ticket coalesces onto a schedule that is about to
+        // decide's STOP releases it, so the ticket coalesces onto a schedule that is about to
         // die and nothing ever nudges about it. Forcing that exact thread interleaving is not
-        // reliable, so this drives stopOrRestartTicketLoop — the STOP path's own release-and-recheck —
+        // reliable, so this drives stopOrRestart — the STOP path's own release-and-recheck —
         // directly, arranging the state it must not lose a ticket in: a ticket pending for the lead
-        // that was NOT part of the pre-decision snapshot (pendingBefore=empty), standing in for one
+        // that was NOT part of the pre-decision snapshot (ticketsBefore=empty), standing in for one
         // that races in during the decision-to-release window.
         var rec = recordingClient();
         agents = new AgentControl(rec);
@@ -358,9 +392,9 @@ class ReplyPushLoopTest {
 
         loop.onTicketTerminal("task-1", WORKER, false); // pendingTickets={task-1}; activeLeads={PRIMARY}
 
-        // Stand in for the scheduler thread reaching decideTickets==STOP for this lead — with nothing
+        // Stand in for the scheduler thread reaching decide==STOP for this lead — with nothing
         // pending at decide time — while task-1 races in before the release below runs.
-        loop.stopOrRestartTicketLoop(PRIMARY, Set.of());
+        loop.stopOrRestart(PRIMARY, Set.of(), Set.of());
 
         assertTrue(loop.isActive(), "a ticket that raced the loop's stop must reclaim the schedule "
                 + "slot, not be stranded with no schedule left to ever nudge about it");
@@ -368,23 +402,67 @@ class ReplyPushLoopTest {
 
     @Test
     void aStaleUncollectedTicketAtCapDoesNotRestartTheLoop() {
-        // The other direction of the same fix: restarting on ANY non-empty pendingFor(lead) would be
+        // The other direction of the same fix: restarting on ANY non-empty pending set would be
         // wrong. When STOP is reached because the reminder cap was hit, the same never-collected
         // ticket is expected to still be there — that is the cap doing its job (acceptance criterion
-        // #7: nudges stay bounded). task-1 here was already accounted for at decide time (it is in
-        // pendingBefore), so it must not restart the loop just because it is still sitting there.
+        // #5: no spin / nudges stay bounded). task-1 here was already accounted for at decide time
+        // (it is in ticketsBefore), so it must not restart the loop just because it is still sitting
+        // there.
         var rec = recordingClient();
         agents = new AgentControl(rec);
         ReplyPushLoop loop = loop(1, 100_000);
 
         loop.onTicketTerminal("task-1", WORKER, false); // pendingTickets={task-1}; activeLeads={PRIMARY}
 
-        loop.stopOrRestartTicketLoop(PRIMARY, Set.of("task-1"));
+        loop.stopOrRestart(PRIMARY, Set.of(), Set.of("task-1"));
 
         assertFalse(loop.isActive(), "a stale ticket already accounted for at decide time must not "
                 + "restart the loop — that would defeat the reminder cap");
     }
 
+    // --- mirror of the two stopOrRestart tests above, for the reply arm ------------------------
+    //
+    // Both tests above only ever passed Set.of() for repliesBefore, so racedIn's reply branch
+    // (`pendingReplyTargetsFor(lead).stream().anyMatch(t -> !repliesBefore.contains(t))`) was
+    // never exercised by anything other than an always-empty snapshot. The reviewer flagged this:
+    // racedIn is symmetric in the code, and only half of it was pinned by a test.
+
+    @Test
+    void aReplyStillPendingWhenTheLoopStopsIsNotStranded() {
+        // Mirrors aTicketStillPendingWhenTheLoopStopsIsNotStranded: a reply target that raced in
+        // during the decision-to-release window (absent from the "before" snapshot) must reclaim
+        // the schedule slot rather than being stranded with no schedule left to nudge about it.
+        var rec = recordingClient();
+        agents = new AgentControl(rec);
+        inbox.publish(WORKER, "m1", "hello");
+        ReplyPushLoop loop = loop(1, 100_000); // long backoff — no natural tick fires during this test
+
+        loop.onReplyQueued(WORKER); // pendingReplies={term_worker}; activeLeads={PRIMARY}
+
+        loop.stopOrRestart(PRIMARY, Set.of(), Set.of());
+
+        assertTrue(loop.isActive(), "a reply that raced the loop's stop must reclaim the schedule "
+                + "slot, not be stranded with no schedule left to ever nudge about it");
+    }
+
+    @Test
+    void aStaleUncollectedReplyAtCapDoesNotRestartTheLoop() {
+        // Mirrors aStaleUncollectedTicketAtCapDoesNotRestartTheLoop: a reply target already
+        // accounted for at decide time (present in repliesBefore) must not restart the loop —
+        // that is the reminder cap doing its job, not a race.
+        var rec = recordingClient();
+        agents = new AgentControl(rec);
+        inbox.publish(WORKER, "m1", "hello");
+        ReplyPushLoop loop = loop(1, 100_000);
+
+        loop.onReplyQueued(WORKER); // pendingReplies={term_worker}; activeLeads={PRIMARY}
+
+        loop.stopOrRestart(PRIMARY, Set.of(WORKER), Set.of());
+
+        assertFalse(loop.isActive(), "a stale reply target already accounted for at decide time "
+                + "must not restart the loop — that would defeat the reminder cap");
+    }
+
     @Test
     void ticketNudgeFormatIsCorrect() {
         String single = ReplyPushLoop.TICKET_NUDGE_FORMAT.formatted("task-1", "", "task-1");
@@ -402,7 +480,103 @@ class ReplyPushLoopTest {
     void inboxNudgeStillUsesTheOriginalTargetPollCall() {
         String nudge = ReplyPushLoop.NUDGE_FORMAT.formatted(WORKER, WORKER);
         assertTrue(nudge.contains("bridge_poll(target=" + WORKER + ")"),
-                "CB-588 must not change the CB-307 inbox nudge's call shape");
+                "CB-588/CB-590 must not change the CB-307 inbox nudge's call shape");
+    }
+
+    // --- CB-590: one schedule per lead — no overlap, no lost nudges -----------------------------
+
+    @Test
+    void replyAndTicketForTheSameLeadCoalesceIntoOneSendNeverOverlapping() throws Exception {
+        var rec = recordingClient();
+        agents = new AgentControl(rec);
+        inbox.publish(WORKER, "m1", "hello");
+        var loop = loop(1, 300); // backoff wide enough that both entry points land before the first tick
+
+        loop.onReplyQueued(WORKER);
+        loop.onTicketTerminal("task-1", WORKER, false);
+
+        assertTrue(rec.sendLatch.await(3, TimeUnit.SECONDS), "one combined nudge should have been sent");
+        Thread.sleep(300);
+        assertEquals(1, rec.sendCount(),
+                "a reply and a ticket for the same lead must coalesce onto ONE schedule — "
+                        + "two nudge injections into the same lead pane must never overlap");
+        String nudge = rec.sentParams().getFirst().getValue().toString();
+        assertTrue(nudge.contains("bridge_poll(target=" + WORKER + ")"),
+                "the combined nudge must still mention the reply: " + nudge);
+        assertTrue(nudge.contains("task-1"), "the combined nudge must still mention the ticket: " + nudge);
+    }
+
+    @Test
+    void aReplyQueuedWhileTheLeadIsBusyIsNotLostWhenATicketArrivesToo() throws Exception {
+        // The lead is busy for its first two status checks, then becomes injectable. A reply is
+        // queued while busy; a ticket for the same lead arrives before the lead frees up. Neither
+        // may be dropped — deferred is fine, lost is not (acceptance criterion #2).
+        var rec = new BusyThenIdleHerdrClient(2);
+        agents = new AgentControl(rec);
+        inbox.publish(WORKER, "m1", "hello");
+        var loop = loop(1, 50); // cap=1: WAIT_BUSY doesn't count against it, so exactly one send once injectable
+
+        loop.onReplyQueued(WORKER);                     // schedule starts, first tick(s) WAIT_BUSY
+        loop.onTicketTerminal("task-1", WORKER, false);  // coalesces onto the same waiting schedule
+
+        assertTrue(rec.sendLatch.await(3, TimeUnit.SECONDS),
+                "once the lead becomes injectable, the deferred work must still be nudged");
+        Thread.sleep(200);
+        assertEquals(1, rec.sendCount(), "exactly one nudge once injectable — reply and ticket coalesced");
+        String nudge = rec.sentParams().getFirst().getValue().toString();
+        assertTrue(nudge.contains("bridge_poll(target=" + WORKER + ")"), "the reply must not be dropped: " + nudge);
+        assertTrue(nudge.contains("task-1"), "the ticket must not be dropped: " + nudge);
+    }
+
+    // --- CB-590 follow-up: per-source reminder budgets — the regression this round exists for ---
+
+    @Test
+    void oneExhaustedSourceDoesNotBlockANudgeForTheOtherSource() {
+        // The live trace this ticket was filed from: an undrained reply target got nudged up to
+        // its cap (5 reminders), then a ticket for the SAME lead went terminal shortly before the
+        // next scheduled tick — so it coalesced onto the still-active schedule (arriving BEFORE
+        // that tick's "before" snapshot, not during the decision-to-release race stopOrRestart
+        // guards). With CB-590's single shared reminder counter, that tick's decide() saw
+        // reminderCount already at the cap and returned STOP regardless of the ticket, and because
+        // the ticket was already present in that tick's "before" snapshot, stopOrRestart's
+        // racedIn check (proven correct on its own above) did not save it either — it is not a
+        // race, it looks like ordinary stale backlog. The ticket was then stranded: pending
+        // forever with no live schedule, never named in any nudge.
+        //
+        // Fixed by giving each source its own counter. Here the reply source is AT its cap (2/2)
+        // and the ticket source has NEVER been nudged (0/2) — decide() must still return INJECT,
+        // because the ticket is still eligible on its own budget.
+        agents = agentWithStatus("idle");
+        inbox.publish(WORKER, "m1", "hello");
+        var loop = loop(2, 100_000); // huge backoff — this test drives decide()/isActive() directly
+        loop.onReplyQueued(WORKER);
+        loop.onTicketTerminal("task-1", WORKER, false);
+
+        assertEquals(ReplyPushLoop.Action.INJECT, loop.decide(PRIMARY, 2, 0),
+                "the reply source is exhausted (2/2), but the ticket source has never been "
+                        + "nudged (0/2) — the lead must still be injected so the ticket is not "
+                        + "lost, exactly the CB-590 follow-up regression");
+
+        // isActive() (criterion #5): a real tick that takes the INJECT branch above never calls
+        // stopOrRestart, so the schedule started by onTicketTerminal above stays live — the
+        // ticket is not left stranded with isActive()==false while it is still pending.
+        assertTrue(loop.isActive(), "the schedule must stay active while the ticket source still "
+                + "has budget left, even though the reply source sharing it is exhausted");
+    }
+
+    @Test
+    void bothSourcesExhaustedIsStillStop() {
+        // The flip side: per-source budgets must not turn into unbounded nudging. When BOTH
+        // sources are at their cap, decide() must still STOP — a per-source budget is still a
+        // budget.
+        agents = agentWithStatus("idle");
+        inbox.publish(WORKER, "m1", "hello");
+        var loop = loop(2, 100_000);
+        loop.onReplyQueued(WORKER);
+        loop.onTicketTerminal("task-1", WORKER, false);
+
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 2, 2),
+                "both the reply and the ticket source are at their own cap — must still stop");
     }
 
     // --- metrics (CB-512) ----------------------------------------------------------------------
@@ -430,8 +604,10 @@ class ReplyPushLoopTest {
         agents = agentWithStatus("idle");
         inbox.publish(WORKER, "m1", "hello");
         Metrics metrics = new Metrics();
+        var loop = loop(2, 100, metrics);
+        loop.onReplyQueued(WORKER);
 
-        assertEquals(ReplyPushLoop.Action.STOP, loop(2, 100, metrics).decide(WORKER, 2));
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 2, 0));
 
         assertEquals(1, metrics.count(BridgedMetrics.PUSH_NUDGES, "outcome", "exhausted"),
                 "hitting the reminder cap must count as exhausted");
@@ -459,7 +635,7 @@ class ReplyPushLoopTest {
         var loop = loop(2, 100_000, metrics);
         loop.onTicketTerminal("task-1", WORKER, false);
 
-        assertEquals(ReplyPushLoop.Action.STOP, loop.decideTickets(PRIMARY, 2));
+        assertEquals(ReplyPushLoop.Action.STOP, loop.decide(PRIMARY, 0, 2));
 
         assertEquals(1, metrics.count(BridgedMetrics.PUSH_NUDGES, "outcome", "exhausted"),
                 "hitting the ticket reminder cap must count as exhausted");
@@ -547,4 +723,49 @@ class ReplyPushLoopTest {
     private static RecordingHerdrClient recordingClient() {
         return new RecordingHerdrClient();
     }
+
+    /**
+     * Thread-safe fake that reports {@code working} (not injectable) for its first
+     * {@code busyChecks} status calls, then {@code idle} forever after — used to prove work queued
+     * while the lead is busy is deferred, not dropped, once it becomes injectable.
+     */
+    private static final class BusyThenIdleHerdrClient implements HerdrClient {
+        private final List<Map.Entry<String, Object>> calls =
+                Collections.synchronizedList(new ArrayList<>());
+        private final AtomicInteger statusChecks = new AtomicInteger();
+        private final int busyChecks;
+        volatile CountDownLatch sendLatch = new CountDownLatch(1);
+
+        BusyThenIdleHerdrClient(int busyChecks) {
+            this.busyChecks = busyChecks;
+        }
+
+        @Override
+        public JsonNode call(String method, Object params) {
+            if ("agent.get".equals(method)) {
+                String status = statusChecks.getAndIncrement() < busyChecks ? "working" : "idle";
+                return MAPPER.createObjectNode()
+                        .set("agent", MAPPER.createObjectNode()
+                                .put("terminal_id", PRIMARY)
+                                .put("agent_status", status));
+            }
+            if ("agent.prompt".equals(method)) {
+                calls.add(Map.entry(method, params));
+                sendLatch.countDown();
+            }
+            return MAPPER.createObjectNode();
+        }
+
+        long sendCount() {
+            return calls.size();
+        }
+
+        List<Map.Entry<String, Object>> sentParams() {
+            return List.copyOf(calls);
+        }
+
+        @Override
+        public void close() {
+        }
+    }
 }

bridged/src/test/java/dev/ltms/bridged/rest/BridgedAppTest.java

@@ -18,6 +18,8 @@ import dev.ltms.bridged.session.GitWorktrees;
 import dev.ltms.bridged.session.SessionManager;
 import dev.ltms.bridged.session.Worktrees;
 import dev.ltms.bridged.member.ClaudeCodeLauncher;
+import dev.ltms.bridged.member.CompositePeerLauncher;
+import dev.ltms.bridged.placement.PlacementPolicies;
 import io.javalin.Javalin;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
@@ -240,6 +242,43 @@ class BridgedAppTest {
         assertFalse(herdr.called("agent.start"), "an unknown profile must not spawn anything");
     }
 
+    /**
+     * CB-599: a profile at its {@code maxLoad} cap must not surface as a bare 500 — the caller
+     * needs a structured, readable reason, distinct from "unknown_profile".
+     */
+    @Test
+    void spawnAtMaxLoadIs503WithTheCapacityReasonNotABare500() throws Exception {
+        FakeHerdr herdr = new FakeHerdr();
+        BridgedConfig.Profile wcfg = new BridgedConfig.Profile(
+                "ltms-local", "http://gx00.gw:8000", "coder", null, "BRIDGED_WORKER_TOKEN", null,
+                "tab", "bridged-workers", "worker: {profile} #{n}", null,
+                null, null, null, null, null, null, null, 0, null, null, null);
+        Map<String, BridgedConfig.Profile> profiles = Map.of(wcfg.profile(), wcfg);
+        ClaudeCodeLauncher delegate = new ClaudeCodeLauncher(
+                new AgentControl(herdr), new WorkspaceControl(herdr), new SubscriptionGuard(Set.of("gx00.gw")),
+                profiles, wcfg.profile(), k -> "BRIDGED_WORKER_TOKEN".equals(k) ? "tok-abc" : null);
+        CompositePeerLauncher workers = new CompositePeerLauncher(
+                List.of(delegate), wcfg.profile(), profiles, PlacementPolicies.fixed(), _ -> 0);
+        SessionManager sessions = new SessionManager(workers, new GitWorktrees());
+        this.presence = sessions.asPresence();
+        Injector injector = new Injector(new AgentControl(herdr));
+        InMemoryReplyInbox inbox = new InMemoryReplyInbox();
+        sessions.onAcquire(inbox::own);
+        MessageService messages = new MessageService(new AgentControl(herdr), injector, new Rendezvous(), inbox);
+        app = new BridgedApp(herdr, workers, sessions, messages, this.presence, null).build().start("127.0.0.1", 0);
+        int port = app.port();
+
+        HttpResponse<String> res = req(port, "POST", "/members?profile=ltms-local");
+
+        assertEquals(503, res.statusCode(), res.body());
+        JsonNode body = mapper.readTree(res.body());
+        assertEquals("no_capacity", body.get("error").asText());
+        String detail = body.get("detail").asText();
+        assertTrue(detail.contains("ltms-local"), "detail names the profile: " + detail);
+        assertTrue(detail.contains("maxLoad"), "detail explains the refusal: " + detail);
+        assertFalse(herdr.called("agent.start"), "at cap, the spawn is refused before any herdr call");
+    }
+
     @Test
     void spawnWorkerReusesExistingWorkerSpace() throws Exception {
         // A space labelled "bridged-workers" already exists → no second workspace.create.