fix: event-loop freezes, plugin-install boot crash, tmux attach/scrollbar, Codex transcripts

- GET /api/workflows: one LEAD() window pass in a read worker (read-pool.js,
  workflow-stats.js); idx_events_session restored, idx_events_tool added
- compat-sqlite gains function/pluck/readonly so a plugin install without a
  better-sqlite3 build boots again; antigravity-usage uses db.js's Database
- install-hooks adds no checkout hooks while the agenthub plugin is enabled
  (events were doubled)
- terminal attach runs the live tmux server's own binary; the pane scrollbar
  gets a visible 2-column style, and claude panes start with
  CLAUDE_CODE_DISABLE_ALTERNATE_SCREEN=1 so tmux keeps history to scroll
- Codex sessions' conversation in GET /api/sessions/:id/transcript
- Codex/Antigravity sessions claimed by their workspace without hooks
- UI-audit follow-ups, docs and OpenAPI

server/__tests__/lanes-api.test.js

@@ -1988,4 +1988,25 @@ describe("start: slot auto and a session already live", () => {
     });
     assert.equal(fork.status, 200);
   });
+
+  it("an explicit slot 0 never takes over a terminal tab that holds pane 0", async () => {
+    const dir = fs.mkdtempSync(path.join(os.tmpdir(), "lane-slot0-"));
+    try {
+      const own = (await request("POST", "/api/lanes", { cwd: dir })).body.lane.id;
+      // A terminal tab started on a stopped workspace lands in pane 0 and, being
+      // no run, leaves `run_id` empty.
+      const shell = await request("POST", `/api/lanes/${own}/start`, {
+        slot: "auto",
+        shell: true,
+      });
+      assert.equal(shell.body.run_id, `agenthub-lane-${own}`);
+      for (const body of [{}, { slot: 0 }]) {
+        const r = await request("POST", `/api/lanes/${own}/start`, body);
+        assert.equal(r.status, 409, JSON.stringify(body));
+        assert.equal(r.body.error.code, "ERUNLIVE");
+      }
+    } finally {
+      fs.rmSync(dir, { recursive: true, force: true });
+    }
+  });
 });