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__/tmux.test.js

@@ -52,6 +52,25 @@ describe("tmux wrapper", () => {
       "opus",
     ]);
     assert.deepEqual(calls[1], ["set-option", "-t", "=agenthub-lane-1:", "mouse", "on"]);
+    assert.deepEqual(calls[2], ["set-option", "-t", "=agenthub-lane-1:", "status", "off"]);
+    assert.deepEqual(calls[3], ["set-option", "-t", "=agenthub-lane-1:", "pane-scrollbars", "on"]);
+    assert.deepEqual(calls[4], [
+      "set-option",
+      "-t",
+      "=agenthub-lane-1:",
+      "pane-scrollbars-style",
+      "fg=brightwhite,bg=black,width=2,pad=0",
+    ]);
+  });
+
+  it("newSession still succeeds on a tmux older than 3.7 (no pane-scrollbars)", () => {
+    tmux.__setExecImpl((args) => {
+      if (args.includes("pane-scrollbars")) throw new Error("invalid option: pane-scrollbars");
+      return "";
+    });
+    assert.doesNotThrow(() =>
+      tmux.newSession({ name: "agenthub-lane-1", cwd: "/tmp/repo", argv: ["claude"] })
+    );
   });
 
   it("sendText types the literal string and presses Enter, with no quoting", () => {