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/package-lock.json

@@ -14,6 +14,7 @@
         "@codemirror/view": "^6.43.13",
         "@fontsource/inter": "^5.2.8",
         "@fontsource/jetbrains-mono": "^5.2.8",
+        "@fontsource/maple-mono": "^5.3.0",
         "@xterm/addon-canvas": "^0.7.0",
         "@xterm/addon-clipboard": "^0.1.0",
         "@xterm/addon-fit": "^0.10.0",
@@ -1066,6 +1067,15 @@
         "url": "https://github.com/sponsors/ayuhito"
       }
     },
+    "node_modules/@fontsource/maple-mono": {
+      "version": "5.3.0",
+      "resolved": "https://registry.npmjs.org/@fontsource/maple-mono/-/maple-mono-5.3.0.tgz",
+      "integrity": "sha512-8N3FVDWphO/971tZIig9D558j9jf09fWYIXFjgv7DKJEvDjtgfATx1ScWHdTCsf+tufFS5M1bAa4AumVBKPhSQ==",
+      "license": "OFL-1.1",
+      "funding": {
+        "url": "https://github.com/sponsors/ayuhito"
+      }
+    },
     "node_modules/@jridgewell/gen-mapping": {
       "version": "0.3.13",
       "resolved": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.13.tgz",