#293: wrap the bare tab.close in HerdrPeerLauncher.stop()

The pane is already closed by the time spaces.closeTab runs, so a failing
tab.close is cosmetic workspace tidying, not a real teardown failure. Left
bare, it propagated out of stop() and masked releaseZdotdir (ZDOTDIR leak)
and, worse, SessionManager.release()'s worktree removal (no self-heal,
no retry — the registry entry is already gone by then).

Wrap it in a try/catch that logs a WARN naming the tab id, matching the
"must not mask a real teardown failure above" comment already on
releaseZdotdir. isAlreadyGone is untouched — this continues past *any*
tab.close failure, not just *_not_found, since the failure is cosmetic
regardless of its cause.

Adds FakeHerdr#tabCloseFailsWith/tabCloseFailsForTab (the tab.close
counterpart to #290's paneCloseFailsForPane) plus two tests: one proving
releaseZdotdir still runs (the generated ZDOTDIR is deleted) and one
proving SessionManager.release() still removes the worktree, both with a
non-not_found tab.close failure.

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

@@ -913,9 +913,14 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      * {@link #reapOrphanWorkers() orphan-reap} and spawn-gate-timeout paths, plus any caller that
      * passes a pane directly, keep working without an owning id.
      *
-     * <p>Resolves the tab from the pane <em>before</em> closing it. An already-gone pane/tab
-     * (repeated DELETE, crashed peer) is treated as success; any other failure propagates so a
-     * genuinely failed teardown is not reported as done.
+     * <p>Resolves the tab from the pane <em>before</em> closing it. {@code agents.close} (the pane)
+     * is the one step whose failure means the teardown itself may not have happened: an already-gone
+     * pane (repeated DELETE, crashed peer) is treated as success, but any other failure propagates so
+     * a genuinely failed teardown is not reported as done. {@code spaces.closeTab} (fleetd #293) is
+     * different — by the time it runs the pane is already closed, so it is cosmetic workspace tidying
+     * rather than a real teardown failure, and a failure there is logged and never propagates, so it
+     * cannot mask the two cleanups below it ({@link #releaseZdotdir}, and the caller's worktree
+     * removal in {@code SessionManager.release}).
      */
     @Override
     public void stop(String idOrPane) {
@@ -934,7 +939,18 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
             log.debug("pane.close({}) ignored — already gone: {}", paneId, e.getMessage());
         }
         if (loc != null && loc.tabPaneCount() == 1) {
-            spaces.closeTab(loc.tabId());
+            // fleetd #293: the pane above is already closed by this point, so a failing tab.close is
+            // cosmetic workspace tidying, not a real teardown failure — it must not mask the two
+            // cleanups below it (releaseZdotdir, and the caller's worktree removal). Unlike
+            // agents.close above, this is not narrowed to "already gone": any failure here, whatever
+            // its cause, is one we continue past, so we log it at WARN (not debug) with the tab id a
+            // person can go close by hand.
+            try {
+                spaces.closeTab(loc.tabId());
+            } catch (HerdrException e) {
+                log.warn("tab.close({}) failed — the pane is already torn down, so continuing; the "
+                        + "tab may need manual cleanup: {}", loc.tabId(), e.getMessage());
+            }
         } else if (loc != null) {
             log.debug("not closing tab {} — it holds {} panes (not a dedicated peer tab)",
                     loc.tabId(), loc.tabPaneCount());

fleetd/src/test/java/dev/ltms/fleet/herdr/FakeHerdr.java

@@ -43,6 +43,8 @@ public final class FakeHerdr implements HerdrClient {
     private int workerTabPaneCount = 1;
     private String paneCloseErrorCode = null;
     private final Map<String, String> paneCloseErrorCodeFor = new ConcurrentHashMap<>();
+    private String tabCloseErrorCode = null;
+    private final Map<String, String> tabCloseErrorCodeFor = new ConcurrentHashMap<>();
     private String agentSendErrorCode = null;
     private boolean noPanes = false;
     private volatile String agentStatus = "idle"; // steady-state agent.get status
@@ -106,6 +108,26 @@ public final class FakeHerdr implements HerdrClient {
         return this;
     }
 
+    /** Make {@code tab.close} fail with this herdr error code, for every tab. */
+    public FakeHerdr tabCloseFailsWith(String code) {
+        this.tabCloseErrorCode = code;
+        return this;
+    }
+
+    /**
+     * Make {@code tab.close} fail with this herdr error code, but only for the given {@code
+     * tab_id} — every other tab's {@code tab.close} still succeeds. The {@code tab.close}
+     * counterpart to {@link #paneCloseFailsForPane} (fleetd #290): lets a test make exactly one
+     * session's tab teardown fail while proving the rest of {@code stop()} — {@code
+     * releaseZdotdir}, and the caller's worktree removal — still runs (fleetd #293). Named "ForTab"
+     * rather than "ForPane" (unlike its sibling) because {@code tab.close} keys on {@code tab_id},
+     * not a pane id.
+     */
+    public FakeHerdr tabCloseFailsForTab(String tabId, String code) {
+        this.tabCloseErrorCodeFor.put(tabId, code);
+        return this;
+    }
+
     /**
      * Make {@code pane.list} report no panes at all — models a second herdr daemon (CB-185) that
      * simply does not host the pane a {@link PaneLocator} is searching for.
@@ -352,7 +374,17 @@ public final class FakeHerdr implements HerdrClient {
                             .formatted(workerTabPaneCount,
                                     seeded.isEmpty() ? "" : "," + String.join(",", seeded)));
                 }
-                case "tab.close" -> mapper.readTree("{\"type\":\"ok\"}");
+                case "tab.close" -> {
+                    Object tabIdParam = params instanceof Map<?, ?> m ? m.get("tab_id") : null;
+                    String perTabCode = tabIdParam == null ? null
+                            : tabCloseErrorCodeFor.get(String.valueOf(tabIdParam));
+                    String code = perTabCode != null ? perTabCode : tabCloseErrorCode;
+                    if (code != null) {
+                        throw new HerdrException("herdr error [" + code + "]: tab.close failed",
+                                code, null);
+                    }
+                    yield mapper.readTree("{\"type\":\"ok\"}");
+                }
                 case "pane.get" -> mapper.readTree("""
                         {"type":"pane_info","pane":{"pane_id":"w9:pW","workspace_id":"w9",
                           "tab_id":"w9:t2","agent_status":"idle"}}""");

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

@@ -925,6 +925,71 @@ class ClaudeCodeLauncherTest {
         assertTrue(herdr.called("pane.close"), "stop via handle.id() must close the pane");
     }
 
+    /** A tab-placement launcher with {@code memberCredentials policy=allow-list} under a zsh shell — the
+     * combination that makes {@link HerdrPeerLauncher#spawn} generate a real ZDOTDIR, so {@code
+     * releaseZdotdir}'s effect (the directory's deletion) is observable from a test. */
+    private ClaudeCodeLauncher serviceWithAllowList(FakeHerdr herdr) {
+        FleetConfig.Profile cfg = new FleetConfig.Profile(
+                "ltms-local", "http://gx00.gw:8000", "coder", null, "FLEETD_WORKER_TOKEN",
+                List.of("ccs", "ltms-local"), "tab", "fleetd-workers",
+                "worker: {profile} #{n}", null, null, null);
+        Supplier<FleetConfig.MemberCredentials> creds = () -> new FleetConfig.MemberCredentials(
+                FleetConfig.MemberCredentials.POLICY_ALLOW_LIST, List.of(), List.of(), null);
+        Function<String, String> env = name -> "SHELL".equals(name) ? "/bin/zsh" : null;
+        return new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), Map.of(cfg.profile(), cfg), cfg.profile(),
+                env, 0, System::currentTimeMillis, () -> { }, null, creds);
+    }
+
+    /**
+     * fleetd #293: {@code stop()} used to run {@code spaces.closeTab} bare — any non-{@code
+     * *_not_found} herdr error propagated straight out of {@code stop()}, skipping {@code
+     * releaseZdotdir} entirely (the pane was already closed by that point, so the tab-close failure
+     * is cosmetic, not a real teardown failure). Proves both halves of the fix: {@code stop()} no
+     * longer throws for this failure, and {@code releaseZdotdir} still runs — observed here by the
+     * generated ZDOTDIR actually being deleted, since {@code releaseZdotdir}'s last line is {@code
+     * EnvAllowListScrub.deleteRecursively(dir)}.
+     */
+    @Test
+    @SuppressWarnings("unchecked")
+    void stopStillReleasesZdotdirWhenCloseTabFailsWithANonNotFoundCode() {
+        FakeHerdr herdr = new FakeHerdr();
+        ClaudeCodeLauncher svc = serviceWithAllowList(herdr);
+        PeerHandle handle = svc.spawn(new SpawnRequest(null, null, null));
+        Map<String, Object> tabCreateParams = (Map<String, Object>) herdr.lastCall("tab.create").params();
+        Map<String, String> tabEnv = (Map<String, String>) tabCreateParams.get("env");
+        String zdotdir = tabEnv.get("ZDOTDIR");
+        assertNotNull(zdotdir, "policy=allow-list under a zsh shell must have generated a ZDOTDIR: " + tabEnv);
+        Path dir = Path.of(zdotdir);
+        assertTrue(Files.isDirectory(dir), "the generated ZDOTDIR must exist before stop(): " + dir);
+        herdr.tabCloseFailsForTab("w9:t2", "internal_error");
+
+        Logger logger = (Logger) LoggerFactory.getLogger(HerdrPeerLauncher.class);
+        ListAppender<ILoggingEvent> appender = new ListAppender<>();
+        appender.start();
+        logger.addAppender(appender);
+        try {
+            assertDoesNotThrow(() -> svc.stop(handle.id()),
+                    "fleetd #293: a failing tab.close is cosmetic — it must not propagate out of stop()");
+        } finally {
+            logger.detachAppender(appender);
+        }
+
+        assertTrue(herdr.called("tab.close"), "tab.close was still attempted");
+        assertFalse(Files.exists(dir),
+                "releaseZdotdir must still run and delete the generated ZDOTDIR despite the tab.close "
+                        + "failure: " + dir);
+        String warn = appender.list.stream()
+                .filter(e -> e.getLevel().equals(Level.WARN))
+                .map(ILoggingEvent::getFormattedMessage)
+                .filter(m -> m.contains("tab.close") && m.contains("w9:t2"))
+                .findFirst()
+                .orElse(null);
+        assertNotNull(warn, "the failing tab.close must be logged at WARN naming the tab id — a "
+                + "silently swallowed failure with no message is not an improvement. Log lines: "
+                + appender.list.stream().map(ILoggingEvent::getFormattedMessage).toList());
+    }
+
     // --- CB-519: host-unique id, decoupled from the pane coordinate ------------------------------
 
     @Test

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

@@ -1156,6 +1156,41 @@ class SessionManagerTest {
                 "COMPLETED release of a clean worktree still removes it");
     }
 
+    /**
+     * fleetd #293: {@code HerdrPeerLauncher.stop()} used to run {@code spaces.closeTab} bare — a
+     * failing {@code tab.close} (any code other than {@code *_not_found}) propagated straight out
+     * of {@code stop()}. {@code SessionManager.release} calls {@code launcher.stop(paneId)} with
+     * no try/catch (fleetd #283 wrapped the WORKTREE-removal step further down, not this one), so
+     * the throw happened <em>before</em> that worktree-removal step ever ran — and by then {@code
+     * registry.remove(paneId)} had already run, so a second {@code stop} is a no-op: the worktree
+     * leaked with no retry path. The pane itself is already closed by the time {@code tab.close}
+     * runs, so its failure is cosmetic workspace tidying, not a real teardown failure. The fix
+     * wraps {@code closeTab} inside {@code stop()} so it no longer throws for this reason; this
+     * test proves both halves at once: {@code release()} does not throw, and it still removes the
+     * worktree.
+     */
+    @Test
+    void releaseStillRemovesTheWorktreeWhenCloseTabFails() {
+        FakeHerdr herdr = new FakeHerdr();
+        RecordingWorktrees worktrees = new RecordingWorktrees();
+        SessionManager sessions = sessionManager(herdr, worktrees);
+        MemberSession s = sessions.acquire("ltms-local", null, "/caller/proj", null,
+                new WorktreeRequest("cb-293a", null));
+        // FakeHerdr's pane.get always answers with tab_id "w9:t2" for a tab-placement spawn.
+        herdr.tabCloseFailsForTab("w9:t2", "internal_error");
+
+        assertDoesNotThrow(() -> sessions.release(s.paneId()),
+                "a failing tab.close is cosmetic (the pane is already closed by then) — it must not "
+                        + "propagate out of release()");
+
+        assertTrue(herdr.called("tab.close"), "tab.close was still attempted");
+        assertEquals(List.of(s.worktree()), worktrees.removeCalls(),
+                "release() must still remove the worktree even though tab.close failed — this is "
+                        + "the leak fleetd #293 reports: before the fix, release() never reached this "
+                        + "step at all");
+        assertTrue(sessions.get(s.paneId()).isEmpty(), "the session is still deregistered");
+    }
+
     @Test
     void unchangedRegressionDirtyCompletedReleaseStillPreservesTheWorktree() {
         FakeHerdr herdr = new FakeHerdr();