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/main.tsx

@@ -7,6 +7,7 @@
  * ## Fonts
  * Only Latin subsets of Inter and JetBrains Mono are imported so Vite bundles
  * lean WOFF2 files instead of every glyph subset Google Fonts would serve.
+ * Maple Mono (the terminal's optional rounded font) ships as one file per weight.
  *
  * ## Service worker reload policy
  * On first visit there is no controlling SW yet — we must not reload when the
@@ -62,6 +63,10 @@ import "@fontsource/jetbrains-mono/latin-500.css";
 // visually mangled inside xterm's fixed-width cells.
 import "@fontsource/jetbrains-mono/vietnamese-400.css";
 import "@fontsource/jetbrains-mono/vietnamese-500.css";
+// The rounded terminal font (Settings → Appearance). Its one file already holds
+// the Vietnamese glyphs; a face is only downloaded once something uses it.
+import "@fontsource/maple-mono/400.css";
+import "@fontsource/maple-mono/700.css";
 import App from "./App";
 import { AuthGate } from "./components/AuthGate";
 import { i18nReady } from "./i18n";