Merge CB-560: mark spawned members present (PR #31)

Merging CB-548 made an architect resolve as Role.ARCHITECT, and BridgeMcp
marked MCP presence only for Role.WORKER. So an architect was never present.
That one line broke two things, because SessionManager.asPresence() is the
same object the injector's readiness gate reads:

  * the session never left SPAWNING;
  * Bridged.deliverableTo was false, so the injector held every delivery,
    waited out READINESS_GRACE_POLLS (~60s) and failed the send.

Confirmed live twice, on claude-code and on opencode. Both logged
"session marked failed" then "failed send via turn-stall fallback", neither
of which names the real cause.

Principal.isSpawnedMember() now means "a spawned member with a pane" —
WORKER or ARCHITECT, never PRIMARY. The Bridged.deliverableTo javadoc, which
still stated the worker-only rule as fact, is corrected: it is the clearest
description of this invariant anywhere, and leaving it stale is how the bug
comes back.

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

@@ -428,19 +428,20 @@ public final class Bridged {
     }
 
     /**
-     * The {@link Injector}'s readiness gate (CB-534): a target is deliverable if it is a worker whose
-     * agent has connected the bridge MCP, <em>or</em> a lead.
+     * The {@link Injector}'s readiness gate (CB-534): a target is deliverable if it is a spawned
+     * member whose agent has connected the bridge MCP, <em>or</em> a lead.
      *
-     * <p>The gate exists for one reason — to hold a delivery out of a <em>spawned</em> worker's boot
+     * <p>The gate exists for one reason — to hold a delivery out of a <em>spawned</em> member's boot
      * window, where herdr already reports {@code idle} but the TUI would drop an injected paste. That
      * hazard is a property of spawning. A lead is never spawned: the operator started it and named it
      * (or labelled its tab) only once it was up, so there is no boot window to guard.
      *
      * <p>A lead is also never enrolled in {@link MemberPresence} — {@code BridgeMcp} marks presence
-     * only for a worker, deliberately, since that map doubles as the worker roster's availability
-     * signal and a lead counted there would show up as an available worker. So without the second
-     * disjunct a lead is permanently un-deliverable: every lead→lead send sat on the gate for
-     * {@code READINESS_GRACE_POLLS} (~60s) and then failed having never been typed into the pane.
+     * for every spawned member (worker and architect), deliberately, since that map doubles as the
+     * member roster's availability signal and a lead counted there would show up as an available
+     * member. So without the second disjunct a lead is permanently un-deliverable: every
+     * lead→lead send sat on the gate for {@code READINESS_GRACE_POLLS} (~60s) and then failed
+     * having never been typed into the pane.
      *
      * <p>The lead set is read through the supplier on each call rather than snapshotted, so a lead
      * discovered by {@code leadScan} after startup becomes deliverable without a restart.

bridged/src/main/java/dev/ltms/bridged/auth/Principal.java

@@ -48,7 +48,7 @@ public record Principal(Role role, String terminal, long pid, String name) {
      * made a lead unaddressable: {@link #ownsSession} could never be true for it, so
      * {@code bridge_reply} was refused and one lead could send to another but never be answered.
      * The terminal now means "which pane is this caller", the presence map keys on
-     * {@link #isWorker()} instead, and a lead is a peer that can both send and receive.
+     * {@link #isSpawnedMember()} instead, and a lead is a peer that can both send and receive.
      */
     public static Principal leader(String name, String terminal, long pid) {
         return new Principal(Role.PRIMARY, terminal, pid, name);
@@ -85,6 +85,16 @@ public record Principal(Role role, String terminal, long pid, String name) {
         return role == Role.WORKER;
     }
 
+    /**
+     * Whether this caller is a spawned member with its own pane.
+     *
+     * <p>Both workers and architects are spawned members. A lead is excluded because recording it
+     * as present would count it as an available member in the roster.
+     */
+    public boolean isSpawnedMember() {
+        return role == Role.WORKER || role == Role.ARCHITECT;
+    }
+
     public boolean isAnonymous() {
         return role == Role.ANONYMOUS;
     }

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

@@ -109,10 +109,10 @@ public final class BridgeMcp {
                             ? callers.resolve(req.getRemoteAddr(), req.getRemotePort(),
                                     req.getHeader("Authorization"))
                             : legacyPrincipal(identity, req.getRemoteAddr(), req.getRemotePort());
-                    // CB-532: guard on the ROLE, not on the terminal being null. A named lead now
-                    // carries its pane too, and enrolling a lead in the worker presence map would
-                    // have it counted as an available worker.
-                    if (p.isWorker()) presence.markPresent(p.terminal());
+                    // CB-532: guard on the ROLE, not on the terminal being null. This excludes a
+                    // lead, which carries its pane too, while including every spawned member role.
+                    // Enrolling a lead would count it as an available member in the roster.
+                    markSpawnedMemberPresent(p, presence);
                     return McpTransportContext.create(Map.of(
                             CALLER_TERMINAL, orEmpty(p.terminal()),
                             CALLER_PID, Long.toString(p.pid()),
@@ -365,6 +365,13 @@ public final class BridgeMcp {
         return transport;
     }
 
+    /** Mark a connected spawned member available for the injector readiness gate. */
+    static void markSpawnedMemberPresent(Principal caller, MemberPresence presence) {
+        if (caller.isSpawnedMember()) {
+            presence.markPresent(caller.terminal());
+        }
+    }
+
     /** Graceful shutdown of the MCP server. */
     public void close() {
         server.closeGracefully();

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

@@ -12,6 +12,7 @@ import dev.ltms.bridged.msg.Rendezvous;
 import dev.ltms.bridged.session.FakeWorktrees;
 import dev.ltms.bridged.session.SessionManager;
 import dev.ltms.bridged.peer.MemberRole;
+import dev.ltms.bridged.inject.MemberPresence;
 import dev.ltms.bridged.session.MemberSession;
 import dev.ltms.bridged.session.WorktreeRequest;
 import dev.ltms.bridged.member.ClaudeCodeLauncher;
@@ -404,6 +405,30 @@ class BridgeMcpTest {
         assertDoesNotThrow(() -> messages.ackReply("term_a", msgId));
     }
 
+    @Test
+    void spawnedMembersAreMarkedPresent() {
+        Principal worker = Principal.worker("term_worker", 200);
+        Principal architect = Principal.architect("lead-designer", "term_design", 400);
+        MemberPresence presence = new MemberPresence();
+
+        BridgeMcp.markSpawnedMemberPresent(worker, presence);
+        BridgeMcp.markSpawnedMemberPresent(architect, presence);
+
+        assertTrue(presence.isPresent("term_worker"));
+        assertTrue(presence.isPresent("term_design"));
+    }
+
+    @Test
+    void nonMembersAreNotMarkedPresent() {
+        Principal lead = Principal.leader("opus", "term_lead", 100);
+        MemberPresence presence = new MemberPresence();
+
+        BridgeMcp.markSpawnedMemberPresent(lead, presence);
+        BridgeMcp.markSpawnedMemberPresent(Principal.anonymous(), presence);
+
+        assertFalse(presence.isPresent("term_lead"));
+    }
+
     @Test
     void statusReportsLiveAgentStatus() {
         FakeHerdr blocked = new FakeHerdr().agentStatus("blocked");