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

client/src/lib/__tests__/runWorktree.test.ts

@@ -0,0 +1,29 @@
+/**
+ * @file runWorktree.test.ts
+ * @description The Changes panel's worktree session for a `?run=` pane survives
+ * a poll that misses the run, and follows every real answer.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, it, expect } from "vitest";
+import { runWorktreeSession } from "../runWorktree";
+
+const wt = { worktree: true, sessionId: "s1" };
+
+describe("runWorktreeSession", () => {
+  it("follows the listed run's worktree session", () => {
+    expect(runWorktreeSession(null, "r1", wt)).toEqual({ run: "r1", session: "s1" });
+    expect(runWorktreeSession(null, "r1", { worktree: false, sessionId: "s1" })).toBeNull();
+  });
+
+  it("keeps the last answer through a poll that misses the run", () => {
+    const prev = runWorktreeSession(null, "r1", wt);
+    expect(runWorktreeSession(prev, "r1", undefined)).toEqual({ run: "r1", session: "s1" });
+  });
+
+  it("drops it for another run or no run", () => {
+    const prev = runWorktreeSession(null, "r1", wt);
+    expect(runWorktreeSession(prev, "r2", undefined)).toBeNull();
+    expect(runWorktreeSession(prev, null, undefined)).toBeNull();
+  });
+});

client/src/lib/__tests__/toast.test.ts

@@ -0,0 +1,35 @@
+/**
+ * @file toast.test.ts
+ * @description The toast queue: at most four on screen, and an error — which
+ * stays until dismissed — is never the one pushed out by newer toasts.
+ * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
+ */
+
+import { describe, it, expect, afterEach } from "vitest";
+import { toast, subscribeToasts, dismissToast, type ToastItem } from "../toast";
+
+let current: ToastItem[] = [];
+const unsubscribe = subscribeToasts((items) => (current = items));
+
+afterEach(() => {
+  for (const t of current) dismissToast(t.id);
+});
+
+describe("toast queue", () => {
+  it("keeps an unread error when newer toasts overflow the queue", () => {
+    toast.error("save failed");
+    for (let i = 0; i < 5; i++) toast.success(`copied ${i}`);
+    expect(current).toHaveLength(4);
+    expect(current.map((t) => t.message)).toContain("save failed");
+    expect(current[current.length - 1]?.message).toBe("copied 4");
+  });
+
+  it("still shows the newest toast when only errors are queued", () => {
+    for (let i = 0; i < 4; i++) toast.error(`error ${i}`);
+    toast.info("hello");
+    expect(current).toHaveLength(4);
+    expect(current[current.length - 1]?.message).toBe("hello");
+  });
+});
+
+void unsubscribe;