fleetd #612 step 4 (ranks 1&2): behavioural assembly tests for the exhaustion wirings

Replaces nothing (no existing test covered these call sites through the real
assembly); adds two new FleetdAssembly-driven tests, matching Unit A's pattern
of inspecting FleetdRuntime's real, assembled objects rather than a copy.

- FleetdExhaustedPatternAssemblyTest pins the liveExhaustedPatterns/
  exhaustedPatterns call sites (rank 1 — "the worst consequence in the whole
  sweep": a genuine usage-limit refusal handed back as real completed work)
  together with publishExhaustionSink (rank 2, non-OpenCode half): drives a
  real CompletionResolver through a pane scrape matching a configured
  exhaustedPattern and asserts BACKEND_EXHAUSTED classification plus a real
  BackendQuarantine credential quarantine.

- FleetdOpenCodeExhaustionForwardingAssemblyTest pins forwardingExhaustionSink
  (rank 2, OpenCode half — independent of publishExhaustionSink per the
  ticket) by reflectively reaching the real, assembled OpenCodeLauncher's
  exhaustionSink field (SessionManager.launcher -> CompositePeerLauncher.
  byProfile -> OpenCodeLauncher.exhaustionSink) and proving it forwards into
  the same production BackendQuarantine.

All four call sites (FleetdAssembly.java:164,299,300,327) were each put
through grep-anchor -> line-anchored sed mutation -> mvn -o compile -> full
mvn -o test (named test RED) -> restore -> full mvn -o test (1885/0 GREEN).
Mutating line 327 alone also fails the OpenCode test, confirming the
documented construction-order dependency (forwardingExhaustionSink reads
exhaustionSinkRef, which publishExhaustionSink sets) without weakening either
site's independent pin.

fleetd/src/test/java/dev/ltms/fleet/FleetdExhaustedPatternAssemblyTest.java

@@ -0,0 +1,211 @@
+package dev.ltms.fleet;
+
+import dev.ltms.fleet.config.ConfigRef;
+import dev.ltms.fleet.config.FleetConfig;
+import dev.ltms.fleet.guard.SubscriptionGuard;
+import dev.ltms.fleet.herdr.FakeHerdr;
+import dev.ltms.fleet.herdr.HerdrClient;
+import dev.ltms.fleet.inject.CompletionResolver;
+import dev.ltms.fleet.msg.Rendezvous;
+import dev.ltms.fleet.msg.TurnToken;
+import dev.ltms.fleet.placement.BackendQuarantine;
+import dev.ltms.fleet.session.MemberSession;
+import io.javalin.Javalin;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.OptionalLong;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.LongSupplier;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * fleetd #612 step 4, ranks 1 and 2 (publish side) — {@link FleetdAssembly} lines
+ * {@code liveExhaustedPatterns}/{@code exhaustedPatterns} (CB-578 stage A, the ticket's own "worst
+ * consequence in the whole sweep": a genuine usage-limit refusal handed back to a waiting caller
+ * AS REAL COMPLETED WORK) and {@code Fleetd.publishExhaustionSink(...)} (CB-578 stage B: the
+ * credential that hit the limit is never quarantined). None of these three lines is driven by an
+ * existing test through the real assembly: {@code FleetdExhaustedPatternLookupWiringTest} and
+ * {@code FleetdLiveExhaustedPatternsWiringTest} (fleetd #589) call {@code Fleetd.liveExhaustedPatterns}
+ * / {@code Fleetd.exhaustedPatternLookup} directly as factories, never through {@link
+ * FleetdAssembly#assembleAndStart} — they prove the FACTORY classifies correctly, never that THIS
+ * call site is the one that actually got wired into the running {@link CompletionResolver}. {@link
+ * FleetdBackendQuarantineAssemblyTest} drives {@code BackendQuarantine.withEscalation(...)}
+ * directly, a different call site from {@code publishExhaustionSink} here.
+ *
+ * <p>This test drives the REAL assembled {@link CompletionResolver} ({@link
+ * FleetdRuntime#completion()}) with a profile carrying a configured {@code exhaustedPattern},
+ * through a pane scrape that matches it, and asserts both halves of the production consequence:
+ * (1) the resolution is {@link Rendezvous.Kind#BACKEND_EXHAUSTED}, never a plain completion handed
+ * back as real work, and (2) the profile's credential is actually quarantined afterward, through
+ * the REAL {@link BackendQuarantine} the same assembly built ({@link
+ * FleetdRuntime#mcp()}{@code .quarantineSource().quarantine()}) — never a copy.
+ *
+ * <p>Same {@code ControllableResourcePorts} shape as {@code FleetdCompletionResolverAssemblyTest}:
+ * a fake, advanceable {@code nanoClock} so {@code CompletionResolver.MIN_TURN_NANOS} clears without
+ * a real sleep, and {@link FakeHerdr#readText} to drive the pane scrape.
+ */
+class FleetdExhaustedPatternAssemblyTest {
+
+    private static final class ControllableResourcePorts implements ResourcePorts {
+
+        final FakeHerdr herdr;
+        final AtomicLong nowNanos = new AtomicLong(1_000_000_000L); // arbitrary non-zero start
+        Runnable shutdownHook;
+
+        ControllableResourcePorts(FakeHerdr herdr) {
+            this.herdr = herdr;
+        }
+
+        void advanceSeconds(long seconds) {
+            nowNanos.addAndGet(TimeUnit.SECONDS.toNanos(seconds));
+        }
+
+        @Override
+        public Map<String, String> environment() {
+            return Map.of();
+        }
+
+        @Override
+        public HerdrClient connectHerdr(Path socketPath) {
+            return herdr;
+        }
+
+        @Override
+        public Fleetd.AmqpOpener replyInboxOpener() {
+            return (uri, prefetch) -> {
+                throw new UnsupportedOperationException("replyInboxOpener must not be called — no broker: block");
+            };
+        }
+
+        @Override
+        public Fleetd.LeadMailboxOpener leadMailboxOpener() {
+            return (uri, selfCoordId, prefetch) -> {
+                throw new UnsupportedOperationException("leadMailboxOpener must not be called — no coordinator: block");
+            };
+        }
+
+        @Override
+        public LongSupplier nanoClock() {
+            return nowNanos::get;
+        }
+
+        @Override
+        public LongSupplier wallClockNanos() {
+            return nowNanos::get;
+        }
+
+        @Override
+        public ScheduledExecutorService newScheduler(String purpose) {
+            return Executors.newSingleThreadScheduledExecutor();
+        }
+
+        @Override
+        public void addShutdownHook(Runnable hook) {
+            this.shutdownHook = hook;
+        }
+
+        @Override
+        public void startHttp(Javalin app, String host, int port) {
+            // Deliberately never bind a real port.
+        }
+    }
+
+    private static FleetConfig writeConfig(Path dir, int cooldownSeconds) throws Exception {
+        Path f = dir.resolve("fleetd.yaml");
+        Files.writeString(f, """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                idleSleepGuard:
+                  enabled: false
+                quarantineCooldownSeconds: %d
+                profiles:
+                  exhaustprofile:
+                    baseUrl: http://exhausthost.local:8000
+                    model: sonnet
+                    exhaustedPattern: "usage limit reached"
+                guard:
+                  offSubscriptionHosts:
+                    - exhausthost.local
+                """.formatted(cooldownSeconds));
+        return FleetConfig.load(f);
+    }
+
+    /**
+     * fleetd #589's own description of this gap ({@code Fleetd#exhaustedPatternLookup}'s javadoc):
+     * "the worst consequence in the whole #589 sweep" — a genuine usage-limit refusal stops being
+     * classified as {@code BACKEND_EXHAUSTED} and is handed back to a waiting {@code fleet_send} as
+     * if it were real completed work. Pins {@code FleetdAssembly}'s {@code liveExhaustedPatterns}
+     * AND {@code exhaustedPatterns} lines (rank 1) together with {@code publishExhaustionSink}
+     * (rank 2, the non-OpenCode half) in one flow: classify, then quarantine.
+     */
+    @Test
+    @DisplayName("[BEHAVIOURAL] a scrape matching the profile's exhaustedPattern resolves "
+            + "BACKEND_EXHAUSTED (never a plain completion) and quarantines the credential")
+    void assembledResolverClassifiesExhaustionAndQuarantinesTheCredential(@TempDir Path dir) throws Exception {
+        int cooldownSeconds = 120;
+        FleetConfig cfg = writeConfig(dir, cooldownSeconds);
+        ConfigRef config = new ConfigRef(dir.resolve("fleetd.yaml"), cfg);
+        SubscriptionGuard guard = new SubscriptionGuard(cfg.guard().hostSet());
+        ControllableResourcePorts ports = new ControllableResourcePorts(new FakeHerdr());
+
+        FleetdRuntime runtime = FleetdAssembly.assembleAndStart(new AssemblyInputs(cfg, config, guard), ports);
+        try {
+            MemberSession session = runtime.sessions().acquire("exhaustprofile", null, dir.toString(), null);
+            String target = session.terminalId();
+
+            CompletionResolver completion = runtime.completion();
+            CompletableFuture<Rendezvous.Resolution> waiter = new CompletableFuture<>();
+
+            ports.herdr.readText("idle, nothing yet");
+            completion.onDelivered(target, new TurnToken(target, waiter, null));
+            // The matched text must START the pane line (CompletionResolver.startsWithExhaustion) —
+            // no preceding sentence — for the quarantine side-effect to fire, same as production.
+            ports.herdr.readText("usage limit reached: try again in a few hours");
+            ports.advanceSeconds(3); // clear CompletionResolver.MIN_TURN_NANOS (2s), no real sleep
+            completion.resolveBeforePostAction(target);
+
+            // CONTROL: the waiter must have resolved synchronously at all — if the assembled
+            // CompletionResolver were never actually driven (e.g. a wiring break upstream silently
+            // left the resolver unreachable), this fails loudly before the real assertions below
+            // ever run, rather than passing on an untouched waiter.
+            Rendezvous.Resolution resolution = waiter.getNow(null);
+            assertTrue(resolution != null, "CONTROL: the waiter must have resolved synchronously — "
+                    + "if this is null, the assembled resolver was never actually exercised");
+
+            assertEquals(Rendezvous.Kind.BACKEND_EXHAUSTED, resolution.kind(),
+                    "a scrape matching the profile's configured exhaustedPattern must classify as "
+                            + "BACKEND_EXHAUSTED, not a plain completion handed back as real work — "
+                            + "replacing FleetdAssembly's liveExhaustedPatterns/exhaustedPatterns "
+                            + "lines with their inert forms (Map.of() / target -> null) must fail "
+                            + "this assertion; got: " + resolution);
+            assertTrue(resolution.text().contains("usage limit reached"), resolution.text());
+
+            BackendQuarantine quarantine = runtime.mcp().quarantineSource().quarantine();
+            assertTrue(quarantine.isQuarantined("exhaustprofile"),
+                    "the real publishExhaustionSink-built sink must have quarantined the profile's "
+                            + "credential (effectiveCredentialId() == the profile name here, no "
+                            + "credentialId configured) — replacing FleetdAssembly's "
+                            + "publishExhaustionSink call site with a hardcoded ExhaustionSink.none() "
+                            + "must fail this assertion, since nothing would ever call "
+                            + "quarantine.quarantine(...)");
+            OptionalLong remaining = quarantine.remainingSeconds("exhaustprofile");
+            assertTrue(remaining.isPresent() && remaining.getAsLong() > 0
+                            && remaining.getAsLong() <= cooldownSeconds,
+                    "a fresh quarantine must block for at most the configured base cooldown: " + remaining);
+        } finally {
+            if (ports.shutdownHook != null) ports.shutdownHook.run();
+        }
+    }
+}

fleetd/src/test/java/dev/ltms/fleet/FleetdOpenCodeExhaustionForwardingAssemblyTest.java

@@ -0,0 +1,190 @@
+package dev.ltms.fleet;
+
+import dev.ltms.fleet.config.ConfigRef;
+import dev.ltms.fleet.config.FleetConfig;
+import dev.ltms.fleet.guard.SubscriptionGuard;
+import dev.ltms.fleet.herdr.FakeHerdr;
+import dev.ltms.fleet.herdr.HerdrClient;
+import dev.ltms.fleet.inject.ExhaustionSink;
+import dev.ltms.fleet.member.CompositePeerLauncher;
+import dev.ltms.fleet.member.HerdrPeerLauncher;
+import dev.ltms.fleet.peer.PeerLauncher;
+import dev.ltms.fleet.placement.BackendQuarantine;
+import io.javalin.Javalin;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.lang.reflect.Field;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Map;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.function.LongSupplier;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * fleetd #612 step 4, rank 2 (OpenCode half) — {@link FleetdAssembly}'s {@code
+ * forwardingExhaustionSink} line ({@code Fleetd.forwardingExhaustionSink(exhaustionSinkRef)}),
+ * handed to {@link dev.ltms.fleet.member.OpenCodeLauncher} so its fleetd #175 model-mismatch check
+ * can quarantine a credential before {@code sessions} exists to build the real sink (the
+ * construction-order cycle documented at that call site). The ticket calls this independent from
+ * {@code publishExhaustionSink} (pinned by {@link FleetdExhaustedPatternAssemblyTest}): a credential
+ * that hits a usage limit through THIS path is never quarantined if {@code forwardingExhaustionSink}
+ * is swapped for a hardcoded {@link ExhaustionSink#none()} at that call site — the OpenCode
+ * launcher's own quarantine check keeps compiling and keeps "running", but it permanently talks to
+ * a sink that does nothing, independent of whatever {@code publishExhaustionSink} does later.
+ *
+ * <p>{@code FleetdExhaustionSinkForwardingWiringTest} (fleetd #589) already proves {@code
+ * Fleetd.forwardingExhaustionSink(ref)} forwards to whatever {@code ref} holds — as a bare factory
+ * call, never through {@link FleetdAssembly#assembleAndStart}. It proves nothing about whether
+ * THIS call site is the one FleetdAssembly actually wires into the real {@code OpenCodeLauncher}
+ * it builds, which is exactly the #602/#606-shaped gap this ticket exists to close.
+ *
+ * <p>No accessor on {@link FleetdRuntime} reaches the adapter instances (by design — see that
+ * class's own javadoc: only the final collaborators it owns directly are exposed), so this test
+ * reaches the REAL, assembled {@code OpenCodeLauncher}'s {@code exhaustionSink} field the same way
+ * {@code SessionManager}/{@code CompositePeerLauncher} wire it internally: a short, targeted
+ * reflective walk ({@code SessionManager.launcher} → {@code CompositePeerLauncher.byProfile} →
+ * {@code OpenCodeLauncher.exhaustionSink}) onto the exact object the assembly built — never a copy,
+ * and never a read of the source text. Reflection is used the same way elsewhere in this suite
+ * (e.g. {@code StatusPollerWatchdogTest}) to reach a private collaborator a production constructor
+ * intentionally does not expose a public accessor for.
+ */
+class FleetdOpenCodeExhaustionForwardingAssemblyTest {
+
+    private static final class ControllableResourcePorts implements ResourcePorts {
+
+        final FakeHerdr herdr = new FakeHerdr();
+        final AtomicLong nowNanos = new AtomicLong(1_000_000_000L);
+        Runnable shutdownHook;
+
+        @Override
+        public Map<String, String> environment() {
+            return Map.of();
+        }
+
+        @Override
+        public HerdrClient connectHerdr(Path socketPath) {
+            return herdr;
+        }
+
+        @Override
+        public Fleetd.AmqpOpener replyInboxOpener() {
+            return (uri, prefetch) -> {
+                throw new UnsupportedOperationException("replyInboxOpener must not be called — no broker: block");
+            };
+        }
+
+        @Override
+        public Fleetd.LeadMailboxOpener leadMailboxOpener() {
+            return (uri, selfCoordId, prefetch) -> {
+                throw new UnsupportedOperationException("leadMailboxOpener must not be called — no coordinator: block");
+            };
+        }
+
+        @Override
+        public LongSupplier nanoClock() {
+            return nowNanos::get;
+        }
+
+        @Override
+        public LongSupplier wallClockNanos() {
+            return nowNanos::get;
+        }
+
+        @Override
+        public ScheduledExecutorService newScheduler(String purpose) {
+            return Executors.newSingleThreadScheduledExecutor();
+        }
+
+        @Override
+        public void addShutdownHook(Runnable hook) {
+            this.shutdownHook = hook;
+        }
+
+        @Override
+        public void startHttp(Javalin app, String host, int port) {
+            // Deliberately never bind a real port.
+        }
+    }
+
+    private static FleetConfig writeConfig(Path dir, int cooldownSeconds) throws Exception {
+        Path f = dir.resolve("fleetd.yaml");
+        Files.writeString(f, """
+                bind:
+                  host: 127.0.0.1
+                  port: 8765
+                idleSleepGuard:
+                  enabled: false
+                quarantineCooldownSeconds: %d
+                profiles:
+                  gemini:
+                    kind: opencode
+                    model: google/gemini-2.5-pro
+                """.formatted(cooldownSeconds));
+        return FleetConfig.load(f);
+    }
+
+    /** Reach a declared field by name on {@code target}'s runtime class, bypassing the access check. */
+    private static Object readField(Object target, Class<?> declaringClass, String fieldName) throws Exception {
+        Field field = declaringClass.getDeclaredField(fieldName);
+        field.setAccessible(true);
+        return field.get(target);
+    }
+
+    @Test
+    @DisplayName("[BEHAVIOURAL] the real assembled OpenCodeLauncher's exhaustionSink field forwards "
+            + "an onExhausted call into the real daemon's BackendQuarantine")
+    void assembledOpenCodeLauncherExhaustionSinkQuarantinesTheCredential(@TempDir Path dir) throws Exception {
+        int cooldownSeconds = 90;
+        FleetConfig cfg = writeConfig(dir, cooldownSeconds);
+        ConfigRef config = new ConfigRef(dir.resolve("fleetd.yaml"), cfg);
+        SubscriptionGuard guard = new SubscriptionGuard(cfg.guard().hostSet());
+        ControllableResourcePorts ports = new ControllableResourcePorts();
+
+        FleetdRuntime runtime = FleetdAssembly.assembleAndStart(new AssemblyInputs(cfg, config, guard), ports);
+        try {
+            PeerLauncher launcherField = (PeerLauncher) readField(runtime.sessions(),
+                    runtime.sessions().getClass(), "launcher");
+            // CONTROL: the composite launcher must actually be the real production type with a
+            // "gemini" -> OpenCodeLauncher entry — if this fails, nothing below exercised the real
+            // assembly at all, rather than silently passing on an empty/wrong object.
+            assertTrue(launcherField instanceof CompositePeerLauncher,
+                    "CONTROL: SessionManager.launcher must be the real CompositePeerLauncher the "
+                            + "assembly built, got: " + launcherField);
+            @SuppressWarnings("unchecked")
+            Map<String, HerdrPeerLauncher> byProfile = (Map<String, HerdrPeerLauncher>)
+                    readField(launcherField, CompositePeerLauncher.class, "byProfile");
+            HerdrPeerLauncher adapter = byProfile.get("gemini");
+            assertTrue(adapter != null && adapter.getClass().getSimpleName().equals("OpenCodeLauncher"),
+                    "CONTROL: the 'gemini' profile must resolve to a real OpenCodeLauncher adapter, "
+                            + "got: " + adapter);
+
+            ExhaustionSink sink = (ExhaustionSink) readField(adapter, adapter.getClass(), "exhaustionSink");
+            assertTrue(sink != null, "CONTROL: OpenCodeLauncher.exhaustionSink must never be null");
+
+            // The exact call OpenCodeLauncher.SessionAwareHandle#checkModelMatch makes on a real
+            // model mismatch (fleetd #175): target, reason, and its own already-known profile name.
+            sink.onExhausted("term_gemini_1", "opencode model mismatch (test)", "gemini");
+
+            BackendQuarantine quarantine = runtime.mcp().quarantineSource().quarantine();
+            assertTrue(quarantine.isQuarantined("gemini"),
+                    "the real forwardingExhaustionSink-wired field must have delegated into the "
+                            + "published production sink, which quarantines the profile's credential "
+                            + "('gemini' here — no credentialId configured) — replacing "
+                            + "FleetdAssembly's forwardingExhaustionSink call site with a hardcoded "
+                            + "ExhaustionSink.none() must fail this assertion, since the field read "
+                            + "above would then BE the inert no-op and nothing would ever reach "
+                            + "quarantine.quarantine(...)");
+            assertEquals(cooldownSeconds, quarantine.remainingSeconds("gemini").orElseThrow(
+                    () -> new AssertionError("credential must report a remaining cooldown")));
+        } finally {
+            if (ports.shutdownHook != null) ports.shutdownHook.run();
+        }
+    }
+}