fleetd #342: base tab-cleanup teardown on the pane's real placement, not a delegate's static config

HerdrPeerLauncher.stop() used to gate spaces.locatePane() on usesTabPlacement(),
which reads the delegate's OWN configured profiles. When CompositePeerLauncher's
single-daemon stop() shortcut hands a pane to a delegate that never spawned it
(spawnedBy empty after a daemon restart, herdrDaemonCount()==1), that delegate's
placement config says nothing true about how the pane was actually placed, and a
dedicated tab could be skipped and leaked.

Resolve the tab unconditionally instead — WorkspaceControl#locatePane already
tolerates a missing pane by returning null — and let the existing single-occupant
check (tabPaneCount()==1) be the only thing that decides whether to close it, same
as it already protects a shared tab regardless of declared placement.

Adds a mixed-placement CompositePeerLauncherTest (every existing stop-fallback test
configured both adapters as tab placement, so the mis-routing never showed) and
updates FleetAppTest#stopWorkerInPanePlacementClosesOnlyThePane, whose old
assertion (no pane.get on pane placement) documented exactly the skip this fix
removes.

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

@@ -937,14 +937,20 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
      */
     @Override
     public void stop(String idOrPane) {
-        // Teardown knows only the pane, not which profile spawned it. Attempt tab cleanup when any
-        // profile uses tab placement (so the bridge may have created a dedicated peer tab); the
-        // single-occupant check below is what actually protects the user's shared tabs.
+        // Teardown knows only the pane, not which profile spawned it — and, when this call is
+        // routed here through CompositePeerLauncher's single-daemon stop() shortcut (fleetd #342),
+        // not even which adapter's config actually governed the spawn: the shortcut can hand the
+        // pane to a delegate that never spawned it, whose own profiles say nothing about how THIS
+        // pane was placed. So the decision to look for a tab to clean up is made from the pane's
+        // actual state, not from this delegate's static profile config: resolve the tab
+        // unconditionally and let {@link WorkspaceControl#locatePane} tolerate "not found" (it
+        // returns null rather than throwing); the single-occupant check below is what actually
+        // protects the user's shared tabs, exactly as it always has.
         String paneId = paneByAgentId.remove(idOrPane);
         if (paneId == null) {
             paneId = idOrPane; // raw-pane fallback (reap, gate timeout, pane-addressed callers)
         }
-        WorkspaceControl.PaneLocation loc = usesTabPlacement() ? spaces.locatePane(paneId) : null;
+        WorkspaceControl.PaneLocation loc = spaces.locatePane(paneId);
         try {
             agents.close(paneId);
         } catch (HerdrException e) {
@@ -985,11 +991,6 @@ public abstract class HerdrPeerLauncher implements PeerLauncher {
         }
     }
 
-    /** Whether any configured profile places peers in their own tab (so tabs may need cleanup). */
-    private boolean usesTabPlacement() {
-        return profiles.values().stream().anyMatch(FleetConfig.Profile::tabPlacement);
-    }
-
     /** True when a herdr error means the target is already gone (safe to treat as done). */
     private static boolean isAlreadyGone(HerdrException e) {
         return e.code() != null && e.code().endsWith("_not_found");

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

@@ -299,6 +299,41 @@ class CompositePeerLauncherTest {
                 "two adapter kinds sharing one daemon keep the fallback route");
     }
 
+    @Test
+    void stopThroughTheSingleDaemonShortcutStillClosesTheTabWhenTheFallbackDelegateUsesPanePlacement() {
+        // fleetd #342: the single-daemon shortcut (spawnedBy empty, herdrDaemonCount()==1) always
+        // routes stop() through delegates.getFirst() — here the claude adapter, configured for
+        // PANE placement (its own profiles never create a dedicated tab). The pane being torn
+        // down here actually belongs to the opencode adapter's TAB placement, sharing the same
+        // herdr daemon — mixing placements is the point: every existing stop-fallback test in this
+        // class configures BOTH adapters as "tab", so usesTabPlacement() was true either way and
+        // the mis-routing never showed.
+        //
+        // Before the fix, HerdrPeerLauncher#stop gated tab resolution on usesTabPlacement() of the
+        // delegate it happened to be called through, so the wrongly-routed (pane-placement) claude
+        // adapter never even looked for a tab to close, and the now-empty tab leaked with nothing
+        // to reap it. The fix (fleetd #342) resolves the pane's real tab unconditionally, so the
+        // decision follows the pane's actual placement rather than the fallback delegate's static
+        // config.
+        FakeHerdr herdr = new FakeHerdr();
+        FleetConfig.Profile claudePane = new FleetConfig.Profile("claude", "http://gx00.gw:8000",
+                "coder", null, "FLEETD_WORKER_TOKEN", List.of("claude"), "pane", "fleetd-workers",
+                "w #{n}", null, null, null);
+        ClaudeCodeLauncher claude = new ClaudeCodeLauncher(new AgentControl(herdr), new WorkspaceControl(herdr),
+                new SubscriptionGuard(Set.of("gx00.gw")), Map.of("claude", claudePane), "claude", _ -> null);
+        PeerLauncher composite = new CompositePeerLauncher(List.of(claude, opencodeAdapter(herdr)), "claude");
+
+        // "w9:pW" was never spawned through this composite instance, so spawnedBy has no entry for
+        // it (the same in-memory-cache-miss shape a daemon restart leaves behind) — stop() falls
+        // through to the single-daemon shortcut and hands it to delegates.getFirst() (claude).
+        composite.stop("w9:pW");
+
+        assertTrue(herdr.called("pane.close"), "the pane itself is still closed on every routed path");
+        assertTrue(herdr.called("tab.close"),
+                "the pane's real (sole-occupant) tab must be closed even though the fallback routed "
+                        + "through a delegate configured for pane placement");
+    }
+
     @Test
     void listKeepsBothPanesWhenTwoDaemonsShareAPaneId() {
         // herdr pane ids are per-daemon counters, so two daemons really can both hold w1:p1 on

fleetd/src/test/java/dev/ltms/fleet/rest/FleetAppTest.java

@@ -711,13 +711,21 @@ class FleetAppTest {
 
     @Test
     void stopWorkerInPanePlacementClosesOnlyThePane() throws Exception {
-        FakeHerdr herdr = new FakeHerdr();
+        // fleetd #342: tab-cleanup resolution is no longer skipped based on a profile's declared
+        // placement — a stop() routed through the wrong delegate (e.g. CompositePeerLauncher's
+        // single-daemon shortcut after a daemon restart) could carry a placement config that says
+        // nothing true about how THIS pane was actually placed. So the pane's real tab is now
+        // always resolved, and the single-occupant check below is what protects a pane-placement
+        // peer's shared tab, exactly as it always protected a tab-placement one. Model that
+        // realistically: the peer's pane was split into an existing tab that already held another
+        // occupant, so the tab must never be closed.
+        FakeHerdr herdr = new FakeHerdr().withWorkerTabPaneCount(2);
         int port = start(herdr, "http://gx00.gw:8000", Set.of("gx00.gw"), "pane");
 
         assertEquals(204, req(port, "DELETE", "/members/w9:pW").statusCode());
         assertTrue(herdr.called("pane.close"));
-        assertFalse(herdr.called("tab.close"), "pane placement owns no tab to close");
-        assertFalse(herdr.called("pane.get"), "no tab resolution in pane placement");
+        assertTrue(herdr.called("pane.get"), "tab resolution now always runs, regardless of placement");
+        assertFalse(herdr.called("tab.close"), "pane placement's shared tab must never be closed");
     }
 
     @Test