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/settings/__tests__/ClaudeAgentHubSettings.test.tsx

@@ -78,7 +78,7 @@ beforeEach(() => {
 describe("ClaudeAgentHubSettings", () => {
   it("renders pricing, hook status and CLAUDE_HOME in their own sections", async () => {
     const { container } = render(<ClaudeAgentHubSettings />);
-    expect(await screen.findByText("claude-opus-5-5%")).toBeInTheDocument();
+    expect(await screen.findByText("claude-opus-5-5")).toBeInTheDocument();
     for (const id of ["pricing", "hooks", "claude-home"]) {
       expect(container.querySelector(`section#${id}`)).not.toBeNull();
     }
@@ -96,7 +96,7 @@ describe("ClaudeAgentHubSettings", () => {
     await user.type(input, "/srv/claude");
     const home = container.querySelector("section#claude-home") as HTMLElement;
     const off = confirmYes();
-    await user.click(within(home).getByRole("button"));
+    await user.click(within(home).getByRole("button", { name: "Save" }));
     await waitFor(() => expect(api.settings.claudeHome.set).toHaveBeenCalledWith("/srv/claude"));
     off();
 
@@ -115,7 +115,7 @@ describe("ClaudeAgentHubSettings", () => {
     const home = container.querySelector("section#claude-home") as HTMLElement;
     const reads = vi.mocked(api.settings.info).mock.calls.length;
     const off = confirmYes();
-    await user.click(within(home).getByRole("button"));
+    await user.click(within(home).getByRole("button", { name: "Save" }));
     await waitFor(() => expect(onHomeChanged).toHaveBeenCalledTimes(1));
     off();
     expect(vi.mocked(api.settings.info).mock.calls.length).toBeGreaterThan(reads);