#214: mint a session id on every claude-code spawn, so every member is resumable

fleetd/src/main/java/dev/ltms/fleet/member/ClaudeCodeLauncher.java

@@ -278,18 +278,22 @@ public final class ClaudeCodeLauncher extends HerdrPeerLauncher {
 
     /**
      * Add the Claude-specific session-identity flags to {@code argv} and return the peer's OWN
-     * session id — the resume handle. A resume request passes the prior id via {@code -r} and
-     * returns that id; a fresh named session mints a new UUID, passes it via {@code --session-id},
-     * and returns the mint. The bridge's logical name rides along as {@code -n} when present. When
-     * <em>no</em> identity is requested (sessionName and resumeSessionId both blank) this adds
-     * nothing and returns {@code null}, keeping the legacy no-identity launch byte-identical.
+     * session id — the resume handle. A resume passes the prior id via {@code -r} and returns
+     * that id; every other spawn mints a new UUID, passes it via {@code --session-id}, and
+     * returns the mint. The bridge's logical name rides along as {@code -n} when present.
+     *
+     * <p>fleetd #214: the mint is unconditional. A plain {@code fleet_spawn} passes neither
+     * sessionName nor resumeSessionId, yet the member must still be resumable, and this id is
+     * the only resume handle a claude-code member has — unlike opencode, nothing resolves it
+     * after the launch. Checked against the real binary (claude 2.1.252): the flag is safe on
+     * every spawn. The binary takes only a valid UUID — it refuses any other value at argument
+     * parsing ("Invalid session ID. Must be a valid UUID.") — so the {@code UUID.randomUUID()}
+     * mint is required, not incidental. The only flag interaction the binary documents is with
+     * {@code -r} (both claim the session id), and the resume branch above never combines the two.
      */
     private static String applySessionIdentity(List<String> argv, String sessionName, String resumeSessionId) {
         boolean resuming = resumeSessionId != null && !resumeSessionId.isBlank();
         boolean named = sessionName != null && !sessionName.isBlank();
-        if (!resuming && !named) {
-            return null; // no identity requested — keep the legacy launch byte-identical
-        }
         if (named) {
             argv.add("-n");
             argv.add(sessionName);

fleetd/src/test/java/dev/ltms/fleet/member/ClaudeCodeLauncherTest.java

@@ -262,10 +262,16 @@ class ClaudeCodeLauncherTest {
 
         Map<?, ?> start = (Map<?, ?>) herdr.lastCall("agent.start").params();
         assertEquals("claude", start.get("kind"), "herdr launches the canonical executable by kind");
-        // CB-533: the shared fixture pins model "coder", so the model flag is the whole args list.
         // What this test guards is that argv[0] is NOT repeated — herdr supplies it from `kind`.
-        assertEquals(List.of("--model", "coder"), start.get("args"),
-                "the configured executable is not repeated in args");
+        // fleetd #214: a plain spawn now also carries fleetd's own minted session id.
+        List<String> args = spawnedArgs(herdr);
+        assertFalse(args.contains("claude"), "the configured executable is not repeated in args");
+        int flag = args.indexOf("--session-id");
+        assertTrue(flag >= 0, "a plain spawn mints a session id: " + args);
+        assertDoesNotThrow(() -> UUID.fromString(args.get(flag + 1)), "the minted id is a valid UUID");
+        assertEquals(List.of("--model", "coder"),
+                List.of(args.get(args.size() - 2), args.get(args.size() - 1)),
+                "the CB-533 model flag still trails the launch flags: " + args);
     }
 
     @Test
@@ -278,7 +284,15 @@ class ClaudeCodeLauncherTest {
         assertFalse(args.contains("--append-system-prompt"), "no reply charter without mcpUrl");
         // CB-533: the model flag is independent of the MCP mount — pinning the model is not part of
         // "mount the bridge", so an unmounted worker still runs the model its profile names.
-        assertEquals(List.of("--verbose", "--model", "coder"), args,
+        // fleetd #214: a plain spawn now carries fleetd's own minted session id; drop the two
+        // mint elements when checking the rest of the argv.
+        int flag = args.indexOf("--session-id");
+        assertTrue(flag >= 0, "a plain spawn mints a session id even without a bridge mount: " + args);
+        assertDoesNotThrow(() -> UUID.fromString(args.get(flag + 1)), "the minted id is a valid UUID");
+        List<String> rest = new java.util.ArrayList<>(args);
+        rest.remove(flag + 1);
+        rest.remove(flag);
+        assertEquals(List.of("--verbose", "--model", "coder"), rest,
                 "the operator's own args are preserved, in order, ahead of the model flag");
     }
 
@@ -649,7 +663,7 @@ class ClaudeCodeLauncherTest {
         assertEquals("/work/proj", cwd, "effectiveCwd via SpawnRequest must match the three-arg resolution");
     }
 
-    // --- CB-547a: durable session identity (mint / resume / no-identity legacy) -----------------
+    // --- CB-547a / fleetd #214: durable session identity (always mint / resume) -----------------
 
     @Test
     void freshSpawnMintsASessionIdAndPassesTheName() {
@@ -684,18 +698,28 @@ class ClaudeCodeLauncherTest {
     }
 
     @Test
-    void noIdentitySpawnKeepsTheLegacyArgvAndCarriesNoSessionHandle() {
+    void plainSpawnMintsASessionIdSoEveryMemberIsResumable() {
+        // fleetd #214: a plain spawn passes no sessionName and no resumeSessionId, yet the member
+        // must still be resumable — the id is minted unconditionally, and it is the ONLY resume
+        // handle a claude-code member has (unlike opencode, nothing resolves it after the launch).
+        // The binary requires a valid UUID (checked against claude 2.1.252: a non-UUID is refused
+        // at argument parsing with "Invalid session ID. Must be a valid UUID.").
         FakeHerdr herdr = new FakeHerdr();
         ClaudeCodeLauncher svc = service(herdr, List.of("ccs", "ltms-local"), null);
 
         PeerHandle handle = svc.spawn(new SpawnRequest("ltms-local", null, null));
 
         List<String> args = spawnedArgs(herdr);
-        assertFalse(args.contains("--session-id"), "no identity → no --session-id");
-        assertFalse(args.contains("-n"), "no identity → no -n");
-        assertFalse(args.contains("-r"), "no identity → no -r");
-        assertNull(handle.agentSessionId(), "no identity → no resume handle");
-        assertNull(handle.sessionName(), "no identity → no logical name");
+        int flag = args.indexOf("--session-id");
+        assertTrue(flag >= 0 && flag + 1 < args.size(),
+                "--session-id is minted even when no identity is requested: " + args);
+        String minted = args.get(flag + 1);
+        assertDoesNotThrow(() -> UUID.fromString(minted), "--session-id is a valid UUID: " + minted);
+        assertEquals(minted, handle.agentSessionId(),
+                "the resume handle is the minted id, so every member is resumable from fleet_list");
+        assertFalse(args.contains("-n"), "no sessionName was requested → no -n");
+        assertFalse(args.contains("-r"), "no resume was requested → no -r");
+        assertNull(handle.sessionName(), "no sessionName was requested → no logical name");
     }
 
     @Test

fleetd/src/test/java/dev/ltms/fleet/session/SessionManagerTest.java

@@ -887,15 +887,18 @@ class SessionManagerTest {
     }
 
     @Test
-    void acquireWithNeitherSessionFieldLeavesAgentSessionIdNull() {
+    void acquireWithNeitherSessionFieldStillMintsAnAgentSessionId() {
+        // fleetd #214: the claude-code launcher mints a session id for EVERY spawn, so a member is
+        // resumable even when the spawn asked for no session identity.
         FakeHerdr herdr = new FakeHerdr();
         SessionManager sessions = sessionManager(herdr);
 
         MemberSession s = sessions.acquire("ltms-local", null, null, null);
 
-        assertNull(s.agentSessionId(), "no identity requested — unchanged from before CB-584");
-        assertFalse(SessionManager.rosterView(s, null).containsKey("agentSessionId"),
-                "a null id is omitted from the roster, like charterSha256 for a receipt-less session");
+        assertNotNull(s.agentSessionId(),
+                "fleetd #214: a plain spawn mints a session id, so every member is resumable");
+        assertTrue(SessionManager.rosterView(s, null).containsKey("agentSessionId"),
+                "the minted id is in the roster, so fleet_list advertises every member's resume handle");
     }
 
     @Test