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__/LaneChangesPanel.test.tsx

@@ -34,6 +34,8 @@ vi.mock("../../../lib/api", () => ({
       gitAction: vi.fn(),
       gitLog: vi.fn(),
       gitFile: vi.fn(),
+      gitRawUrl: (id: number, path: string, rev: string) =>
+        `/api/lanes/${id}/git/raw?path=${encodeURIComponent(path)}&rev=${rev}`,
       gitSaveFile: vi.fn(),
       gitLs: vi.fn(),
       gitTree: vi.fn(),
@@ -380,6 +382,32 @@ describe("LaneChangesPanel", () => {
     expect(await screen.findByTestId("lane-file-view")).toHaveTextContent("# Hello");
   });
 
+  it("shows an image file as the picture, with no edit control", async () => {
+    vi.mocked(api.lanes.gitTree).mockResolvedValue({
+      available: true,
+      path: "",
+      entries: [{ name: "logo.png", path: "logo.png", dir: false, status: "" }],
+      truncated: false,
+    });
+    vi.mocked(api.lanes.gitFile).mockResolvedValue({
+      available: true,
+      path: "logo.png",
+      rev: "work",
+      binary: true,
+      truncated: false,
+      lines: [],
+    });
+    const user = userEvent.setup();
+    render(<LaneChangesPanel laneId={7} full />);
+    const sidebar = await screen.findByTestId("lane-changes-sidebar");
+    await user.click(await within(sidebar).findByText("logo.png"));
+    const img = within(await screen.findByTestId("lane-file-image")).getByRole("img");
+    expect(img).toHaveAttribute("src", "/api/lanes/7/git/raw?path=logo.png&rev=work");
+    expect(screen.queryByTestId("lane-file-view")).toBeNull();
+    expect(screen.queryByTestId("lane-file-noedit")).toBeNull();
+    expect(screen.queryByTestId("lane-file-edit")).toBeNull();
+  });
+
   it("at full width shows the tree as a sidebar and opens a file for reading, editing on a click", async () => {
     vi.mocked(api.lanes.gitTree).mockResolvedValue({
       available: true,