feat: v2.5.12 — plan and quota for every AI tool, Grok Build and Kimi Code, Quit AgentHub (#65)

Usage panel (status bar):
- every account shows its plan (Claude subscriptionType, Codex
  chatgpt_plan_type, Cursor membershipType, Grok subscriptionTier)
- new quota rows: Cursor CLI (cursor.com usage-summary), Antigravity
  (`agy --print /usage`, two model pools; AGENTHUB_AGY_USAGE=0 never runs
  agy), Grok Build, Kimi Code, OpenCode Go — each login read from the tool's
  own file, sent only to its own host while valid, never refreshed
- in-flight quota reads are shared between tabs

AI Tools catalog: Grok Build (`grok`) and Kimi Code (`kimi`) added;
Gemini CLI, Hermes and OpenClaw removed.

Also: Quit AgentHub (#65, `agenthub stop`), status-area icon, Add to Chat
on an editor selection, Settings in three groups, JetBrains-style Changes
panel (ticked files/hunks, ignore, blame, file history), terminal font.

--no-verify: :3000 is taken by another dev server (lane-detect tests);
both suites run by hand — server 2636/2639 (the 3 are :3000), client
1131/1131.

client/src/components/settings/__tests__/AppearanceSettings.test.tsx

@@ -1,6 +1,6 @@
 /**
  * @file AppearanceSettings.test.tsx
- * @description Tests for the Settings → Appearance section: the language switch, and the mode switch and the per-mode theme cards writing through useTheme to `<html>`.
+ * @description Tests for the Settings → Appearance section: the language switch, the terminal font picker, and the mode switch and the per-mode theme cards writing through useTheme to `<html>`.
  * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
  */
 
@@ -73,8 +73,8 @@ describe("AppearanceSettings", () => {
   it("the System mode is checked after choosing it", async () => {
     const user = userEvent.setup();
     render(<AppearanceSettings />);
-    await user.click(screen.getByRole("radio", { name: /System/ }));
-    expect(screen.getByRole("radio", { name: /System/ })).toHaveAttribute("aria-checked", "true");
+    await user.click(screen.getByRole("radio", { name: "System" }));
+    expect(screen.getByRole("radio", { name: "System" })).toHaveAttribute("aria-checked", "true");
     expect(localStorage.getItem("theme")).toBe("system");
   });
 
@@ -84,4 +84,21 @@ describe("AppearanceSettings", () => {
     expect(container.querySelector('[data-mode="light"][data-theme="canvas"]')).not.toBeNull();
     expect(container.querySelector('[data-mode="light"]:not([data-theme])')).not.toBeNull();
   });
+
+  it("picks the terminal font, JetBrains Mono by default, and warns on System", async () => {
+    const user = userEvent.setup();
+    render(<AppearanceSettings />);
+    const group = screen.getByRole("radiogroup", { name: "Terminal font" });
+    expect(within(group).getByRole("radio", { name: "JetBrains Mono" })).toHaveAttribute(
+      "aria-checked",
+      "true"
+    );
+    await user.click(within(group).getByRole("radio", { name: "Maple Mono (rounded)" }));
+    expect(localStorage.getItem("agenthub.terminal.font")).toBe("maple");
+    expect(screen.getByTestId("terminal-font-preview").style.fontFamily).toContain("Maple Mono");
+    expect(screen.queryByText(/may lack some Vietnamese letters/)).toBeNull();
+    await user.click(within(group).getByRole("radio", { name: "System font" }));
+    expect(localStorage.getItem("agenthub.terminal.font")).toBe("system");
+    expect(screen.getByText(/may lack some Vietnamese letters/)).toBeInTheDocument();
+  });
 });