feat: workspace aliases, tab groups of split panes, native path picker (v2.1.0)

- /api/workspaces and `agenthub workspace(s)` / `--workspace` as aliases of
  /api/lanes and `agenthub lanes` / `--lane`; old names print one stderr note.
  REPL `help lanes|workspace|workspaces` resolves through the aliases.
- A workspace holds up to ten sessions (slots 0-9); every console tab is a
  group of 1-4 split panes (PaneGroups, agenthub.workspace.paneLayout);
  parseGroups keeps the stored active tab when an earlier one is dropped.
- Browse button beside path fields: POST /api/lanes/pick-path opens the OS
  picker on the server's desktop — loopback only and no forwarding header
  (EREMOTE), a display failure is ENODIALOG not a Cancel, the dialog is
  killed when the request closes, a folder field falls back to the in-app
  browser on any failure.
- Changes rail counts chip, image viewer (/git/raw), status bar session
  counts and per-day cost (`date=` on /api/pricing/cost).
- /agenthub-open and /agenthub-doctor run from the INSTALLED build
  (supersededBy), doctor offers fixes behind two confirmations; plugin-open
  treats a locked bootstrap as non-fatal.
- New-terminal shell waits for the first attach (issue #55).
- repo-onboarding / debug-live-issue skills removed.
- OpenAPI: pick-path, lane/date on /pricing/cost, tool on /run/history,
  /api/workspaces mount.

client/src/components/lanes/__tests__/LaneGitHeader.test.tsx

@@ -1,7 +1,8 @@
 /**
  * @file LaneGitHeader.test.tsx
  * @description Pins the Changes panel's working-copy line: the live branch,
- * head, subject and uncommitted counts, the per-file hover panel behind the
+ * head, subject and uncommitted counts (no hover there — the panel lists the
+ * files below), the per-file hover panel behind the closed rail's vertical
  * counts, that a lane switch drops the previous lane's facts at once, and that
  * an unreadable repo renders nothing rather than an error.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
@@ -9,7 +10,7 @@
 
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render, screen, waitFor, fireEvent } from "@testing-library/react";
-import { LaneGitHeader, useLaneGitFacts } from "../LaneGitHeader";
+import { LaneGitHeader, LaneGitRailCounts, useLaneGitFacts } from "../LaneGitHeader";
 import { api } from "../../../lib/api";
 
 vi.mock("../../../lib/api", () => ({
@@ -70,9 +71,9 @@ describe("LaneGitHeader", () => {
     expect(screen.queryByText(/feat\/rename-metric/)).toBeNull();
   });
 
-  it("names the files behind the counts on hover, with each one's line delta", async () => {
+  it("names the files behind the rail's counts on hover, with each one's line delta", async () => {
     vi.mocked(api.lanes.git).mockResolvedValueOnce(facts);
-    render(<Harness laneId={1} />);
+    render(<LaneGitRailCounts laneId={1} />);
 
     const counts = await screen.findByTestId("lane-git-counts");
     // Hidden until asked for: the row is a one-line summary until you hover.
@@ -98,7 +99,7 @@ describe("LaneGitHeader", () => {
 
   it("stays open while the pointer is inside the panel", async () => {
     vi.mocked(api.lanes.git).mockResolvedValueOnce(facts);
-    render(<Harness laneId={1} />);
+    render(<LaneGitRailCounts laneId={1} />);
 
     const counts = await screen.findByTestId("lane-git-counts");
     fireEvent.mouseEnter(counts);
@@ -115,12 +116,27 @@ describe("LaneGitHeader", () => {
   it("says how many files the server-side cap left out", async () => {
     // 40 uncommitted files, 3 listed: the counts are exact, the listing is not.
     vi.mocked(api.lanes.git).mockResolvedValueOnce({ ...facts, dirty: 39, untracked: 1 });
-    render(<Harness laneId={1} />);
+    render(<LaneGitRailCounts laneId={1} />);
 
     fireEvent.mouseEnter(await screen.findByTestId("lane-git-counts"));
     expect(screen.getByTestId("lane-git-files").textContent).toContain("37 more");
   });
 
+  it("shows the counts in the open panel's header without the hover list", async () => {
+    vi.mocked(api.lanes.git).mockResolvedValueOnce(facts);
+    render(<Harness laneId={1} />);
+    const counts = await screen.findByTestId("lane-git-counts");
+    fireEvent.mouseEnter(counts);
+    fireEvent.focus(counts);
+    expect(screen.queryByTestId("lane-git-files")).toBeNull();
+  });
+
+  it("draws the rail's counts vertical", async () => {
+    vi.mocked(api.lanes.git).mockResolvedValueOnce(facts);
+    render(<LaneGitRailCounts laneId={1} />);
+    expect((await screen.findByTestId("lane-git-counts")).className).toContain("vertical-rl");
+  });
+
   it("omits the uncommitted line when the tree is clean", async () => {
     vi.mocked(api.lanes.git).mockResolvedValueOnce({ ...facts, dirty: 0, untracked: 0 });
     render(<Harness laneId={1} />);