CB-565: remove unsafe session recycle

bridged/src/main/java/dev/ltms/bridged/session/SessionManager.java

@@ -29,8 +29,7 @@ import java.util.function.LongSupplier;
  * teardown on top.
  *
  * <p>The state machine is intentionally one-shot / no-reuse: every acquired worker is fresh,
- * and a finished or released worker is torn down, never pooled. {@link #recycle} is a convenience
- * for {@code release + acquire} with a new distinct pane id.
+ * and a finished or released worker is torn down, never pooled or reused.
  *
  * <p>The manager implements {@link TurnListener} so the injector's turn boundaries drive
  * {@code READY → BUSY → DONE} (or {@code FAILED}). It exposes a {@link MemberPresence} view via
@@ -180,7 +179,7 @@ public final class SessionManager implements TurnListener {
      * <p>CB-544: these are two concerns that used to be fused. Stopping the pane is correct on every
      * teardown — the worker process must end. Removing the worktree is a destructive act that is only
      * correct for a deliberately-finished teardown (an explicit stop of a completed session, the
-     * reaper releasing a genuinely idle one, a context-capped or recycled session). A shutdown drain
+     * reaper releasing a genuinely idle one, or a context-capped session). A shutdown drain
      * must stop panes but preserve worktrees: a worker's uncommitted work exists in exactly one
      * place — its worktree — so deleting it while the daemon simply goes down is silent data loss,
      * with no copy and no error. Do NOT fuse these back together; the cost of an orphaned worktree
@@ -248,7 +247,7 @@ public final class SessionManager implements TurnListener {
     /**
      * Register a callback invoked with a session's {@code terminalId} whenever it is released
      * (CB-516). Every teardown path funnels through {@link #release}, so one hook covers the REST
-     * and MCP stop tools, the idle-TTL reaper, {@code recycle}, and shutdown drain alike.
+     * and MCP stop tools, the idle-TTL reaper, and shutdown drain alike.
      *
      * <p>Added rather than injected because {@code MessageService} — one intended listener — is
      * constructed after this manager (it needs the injector and rendezvous, which need the session
@@ -370,19 +369,6 @@ public final class SessionManager implements TurnListener {
         return launcher.defaultProfile();
     }
 
-    /**
-     * Release the old session and acquire a fresh one with the same profile and working directory.
-     * The new session is guaranteed to have a pane id distinct from the old one (no-reuse invariant).
-     */
-    public MemberSession recycle(String paneId) {
-        MemberSession old = registry.get(paneId);
-        if (old == null) {
-            throw new IllegalArgumentException("no session for paneId " + paneId);
-        }
-        release(paneId);
-        return acquire(old.profile(), old.cwd(), old.cwd(), old.ownerTerminal());
-    }
-
     /** The session for {@code paneId}, if it is still registered and not released. */
     public Optional<MemberSession> get(String paneId) {
         return Optional.ofNullable(registry.get(paneId));

bridged/src/test/java/dev/ltms/bridged/session/SessionManagerTest.java

@@ -157,35 +157,6 @@ class SessionManagerTest {
         assertTrue(sessions.roster().contains(updated), "FAILED is still in acquired-minus-released roster");
     }
 
-    @Test
-    void recycleProducesNewPaneIdAndOldOneIsGone() {
-        FakeHerdr herdr = new FakeHerdr();
-        SessionManager sessions = sessionManager(herdr);
-        MemberSession oldSession = sessions.acquire("ltms-local", null, "/caller", "term_primary");
-        String oldPane = oldSession.paneId();
-        String oldTerminal = oldSession.terminalId();
-
-        MemberSession fresh = sessions.recycle(oldPane);
-
-        assertNotEquals(oldPane, fresh.paneId(), "recycle yields a new pane id");
-        assertNotEquals(oldTerminal, fresh.terminalId(), "recycle yields a new terminal id");
-        assertEquals(oldSession.profile(), fresh.profile(), "profile is preserved");
-        assertEquals(oldSession.cwd(), fresh.cwd(), "cwd is preserved");
-        assertEquals(oldSession.ownerTerminal(), fresh.ownerTerminal(), "owner is preserved");
-
-        assertTrue(sessions.get(oldPane).isEmpty(), "old pane is deregistered");
-        assertEquals(1, sessions.roster().size(), "only the fresh session remains");
-        assertEquals(fresh.paneId(), sessions.roster().getFirst().paneId());
-
-        // The old session was the first spawn → pane w9:pRoot_1 (CB-519: the registry key is the
-        // uuid id, so teardown is asserted on the real pane coordinate).
-        long paneCloseCount = herdr.calls.stream()
-                .filter(c -> "pane.close".equals(c.method()))
-                .filter(c -> "w9:pRoot_1".equals(((Map<?, ?>) c.params()).get("pane_id")))
-                .count();
-        assertEquals(1, paneCloseCount, "the old worker was torn down");
-    }
-
     @Test
     void rosterReflectsAcquiredMinusReleased() {
         FakeHerdr herdr = new FakeHerdr();

docs/CB-301-Session-Manager.md

@@ -35,7 +35,7 @@ build on.
 - **No checkpoint content.** Writing `STATE.md` + commit on teardown is CB-302; CB-301 only exposes
   the release hook it will attach to.
 
-"Recycle" under no-reuse is simply **release + fresh acquire** — a helper, not a pool operation.
+Under no-reuse, a released session is terminal. A new `acquire` always creates a fresh session.
 
 ## Design
 
@@ -46,11 +46,6 @@ ownership on top.
 **Package:** new `dev.ltms.bridged.session` — keeps the registry/lifecycle concern separate from
 the `worker` spawn mechanics. Holds `SessionManager` + `WorkerSession`.
 
-**`recycle` is IN SCOPE for CB-301** (decided): implement `recycle(paneId, …)` = `release` the old
-session then `acquire` a fresh one, asserting a new distinct paneId (the no-reuse invariant). It is
-a thin convenience over the two primitives, shipped now so the no-reuse teardown+respawn path is
-covered by a test from day one.
-
 ### `WorkerSession` (record or small mutable holder)
 
 | Field | Source | Notes |
@@ -88,7 +83,6 @@ SPAWNING|READY|BUSY|DONE --vanished/drop--> FAILED
 final class SessionManager {
     WorkerSession acquire(String profile, String requestedCwd, String callerCwd, String ownerTerminal);
     void          release(String paneId);          // deterministic teardown + deregister
-    WorkerSession recycle(String paneId, ...);      // release + acquire (no-reuse convenience)
     Optional<WorkerSession> get(String paneId);
     List<WorkerSession> roster();                   // bridge-owned view (CB-304 consumes this)
     // lifecycle hooks (package-private): onReady/onDelivered/onComplete/onFailed(target)
@@ -120,8 +114,7 @@ final class SessionManager {
 3. `release` tears the worker down via `WorkerService.stop` and removes it from `roster()`;
    a second `release` on the same paneId is a harmless no-op.
 4. `onTurnFailed` / drop moves the session to `FAILED` and it is absent from the live roster.
-5. `recycle` produces a new paneId and the old one is gone (no-reuse invariant).
-6. `roster()` reflects exactly the sessions acquired-minus-released, joined with live status.
+5. `roster()` reflects exactly the sessions acquired-minus-released, joined with live status.
 
 ## Seams left open (deliberately)