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.

server/openapi-extra/misc.js

@@ -6,6 +6,8 @@
  *   - PUT    /api/settings/claude-home         (Settings)
  *   - GET    /api/settings/autostart           (Settings)
  *   - PUT    /api/settings/autostart           (Settings)
+ *   - GET    /api/settings/tray                (Settings)
+ *   - PUT    /api/settings/tray                (Settings)
  *   - GET    /api/workflows/runs               (Workflows)
  *   - GET    /api/workflows/runs/{runId}       (Workflows)
  *   - GET    /api/remote-sources               (Remote Sources)
@@ -1064,6 +1066,60 @@ const paths = {
     };
   })(),
 
+  "/api/settings/tray": (() => {
+    const status = {
+      description: "Status-area icon state",
+      content: {
+        "application/json": {
+          schema: {
+            type: "object",
+            required: ["available", "enabled", "running"],
+            properties: {
+              available: {
+                type: "boolean",
+                description: "False in server mode, or on Linux with no graphical session",
+              },
+              enabled: { type: "boolean", description: "On by default" },
+              running: { type: "boolean", description: "The icon process is heartbeating" },
+            },
+          },
+        },
+      },
+    };
+    return {
+      get: {
+        tags: ["Settings"],
+        summary: "Whether AgentHub's icon shows in the OS status area",
+        operationId: "getTray",
+        responses: { 200: status },
+      },
+      put: {
+        tags: ["Settings"],
+        summary: "Show or hide the status-area icon",
+        description:
+          "Clears or writes `<data dir>/runtime/tray-off` and starts or stops the icon process. Never touches the server. Same-origin only.",
+        operationId: "setTray",
+        requestBody: {
+          required: true,
+          content: {
+            "application/json": {
+              schema: {
+                type: "object",
+                required: ["enabled"],
+                properties: { enabled: { type: "boolean" } },
+              },
+            },
+          },
+        },
+        responses: {
+          200: { ...status, description: "The new state" },
+          400: { description: "EBADVALUE: `enabled` is not a boolean" },
+          403: { description: "EBADORIGIN: another site asked" },
+        },
+      },
+    };
+  })(),
+
   "/api/settings/codex-hooks": (() => {
     const status = {
       description: "Where AgentHub's Codex hooks stand",