fix: close three stale-completion holes from the round-16 suppressed block (#2144)

Copilot's round 16 reported "no new comments", but its suppressed block carried
three real findings.

- `AuthTab` released `clearInFlightRef` before checking whether the completion
  was still current, so server A settling after the user moved to B and started
  a clear there dropped B's lock and let a second B clear run concurrently
  against the same store entry. `current()` is now checked before either shared
  ref is touched: a stale clear owns nothing.
- Switching servers retired the clear but left `ownClearRef` set. The retired
  clear returns before its `oauthRevision` bump, so the marker had no bump to
  skip and would swallow the first unrelated revision on the newly selected
  server, stranding that server's banner.
- The web session check compared only the server id, which a
  disconnect/reconnect to the SAME server passes — that flow builds a
  replacement `InspectorClient`, so the old clear would have run its
  session-wide cleanup against the new session. The client identity is part of
  the check now.

Both new tests were verified to fail with their fix reverted.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>

clients/web/src/hooks/useOAuthRecovery.test.tsx

@@ -1409,6 +1409,50 @@ describe("useOAuthRecovery", () => {
       expect(client.disconnect).not.toHaveBeenCalled();
     });
 
+    // A disconnect/reconnect to the SAME server builds a replacement client, so
+    // an id-only check passes again and the old clear would run its
+    // session-wide cleanup — including the disconnect — against the new session.
+    it("does not disconnect a replacement client for the same server", async () => {
+      let settle: (r: { cleared: boolean }) => void = () => {};
+      clearServerOAuthStateMock.mockImplementation(
+        () =>
+          new Promise((resolve) => {
+            settle = resolve as typeof settle;
+          }),
+      );
+      const original = fakeClient();
+      const h = harness({
+        servers: [entry("a")],
+        activeServerId: "a",
+        client: original,
+      });
+
+      let done: Promise<void>;
+      await act(async () => {
+        done = h.api().clearServerOAuthAndDisconnect(entry("a"));
+        await Promise.resolve();
+      });
+
+      // Same server, new client — a reconnect while the clear is pending.
+      const replacement = fakeClient();
+      h.rerender({
+        servers: [entry("a")],
+        activeServerId: "a",
+        client: replacement,
+      });
+
+      await act(async () => {
+        settle({ cleared: true });
+        await done;
+      });
+
+      // Neither client is torn down: the replacement is the live session and
+      // must not be touched, and the original is already gone — disconnecting
+      // it would only drag `finalizeExplicitDisconnect` across the new one.
+      expect(original.disconnect).not.toHaveBeenCalled();
+      expect(replacement.disconnect).not.toHaveBeenCalled();
+    });
+
     it("clears the resume snapshot on an explicit disconnect", () => {
       writeOAuthResumeSnapshot({
         version: 1,

clients/web/src/hooks/useOAuthRecovery.ts

@@ -1265,8 +1265,14 @@ export function useOAuthRecovery({
       // The session ref is the live answer. Only the parts that touch the
       // *session* are gated on it; the store write already happened and the
       // toast still belongs to the server the user asked about.
+      // The client identity is part of the check, not just the server id: a
+      // disconnect/reconnect to the SAME server builds a replacement
+      // `InspectorClient`, so an id-only check passes again and the old clear
+      // would run its session-wide cleanup against the new session.
       const stillTargetsActiveSession = (): boolean =>
-        isActive && sessionRef.current.activeServerId === server.id;
+        isActive &&
+        sessionRef.current.activeServerId === server.id &&
+        sessionRef.current.inspectorClient === client;
 
       const { cleared, revocation } = await clearServerOAuthState({
         config: server.config,