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/__tests__/ai-tools-route.test.js

@@ -59,7 +59,7 @@ describe("/api/ai-tools", () => {
     assert.equal(agy.path, path.join(BIN, "agy"));
     assert.equal(agy.resume, true);
     assert.equal(agy.bypass, true);
-    assert.equal(body.tools.find((t) => t.id === "gemini").installed, false);
+    assert.equal(body.tools.find((t) => t.id === "opencode").installed, false);
     assert.equal("args" in agy, false);
   });
 
@@ -76,7 +76,7 @@ describe("/api/ai-tools", () => {
 
   it("answers ENOTOOL / EBADDEFAULT / EBADFIELD", async () => {
     assert.equal((await request("PUT", "/api/ai-tools/nope", { enabled: false })).status, 404);
-    const bad = await request("PUT", "/api/ai-tools/gemini", { default: true });
+    const bad = await request("PUT", "/api/ai-tools/opencode", { default: true });
     assert.equal(bad.status, 400);
     assert.equal(bad.body.error.code, "EBADDEFAULT");
     assert.equal((await request("PUT", "/api/ai-tools/claude", { enabled: "no" })).status, 400);
@@ -112,10 +112,10 @@ describe("/api/ai-tools", () => {
   });
 
   it("refresh re-detects", async () => {
-    fs.writeFileSync(path.join(BIN, "gemini"), "#!/bin/sh\n");
-    fs.chmodSync(path.join(BIN, "gemini"), 0o755);
+    fs.writeFileSync(path.join(BIN, "opencode"), "#!/bin/sh\n");
+    fs.chmodSync(path.join(BIN, "opencode"), 0o755);
     const r = await request("POST", "/api/ai-tools/refresh");
-    assert.equal(r.body.tools.find((t) => t.id === "gemini").installed, true);
+    assert.equal(r.body.tools.find((t) => t.id === "opencode").installed, true);
   });
 
   it("/api/run/binary resolves through the catalog", async () => {
@@ -132,9 +132,9 @@ describe("lanes on catalog tools", () => {
       fs.mkdirSync(d, { recursive: true });
       return d;
     };
-    let r = await request("POST", "/api/lanes", { cwd: dir("a"), title: "a", tool: "gemini" });
+    let r = await request("POST", "/api/lanes", { cwd: dir("a"), title: "a", tool: "opencode" });
     assert.equal(r.status, 201);
-    assert.equal(r.body.lane.tool, "gemini");
+    assert.equal(r.body.lane.tool, "opencode");
     r = await request("POST", "/api/lanes", { cwd: dir("b"), title: "b", tool: "omp" });
     assert.equal(r.status, 201, "a tool that is not installed may still get a lane");
     r = await request("POST", "/api/lanes", { cwd: dir("c"), title: "c", tool: "nope" });
@@ -212,8 +212,8 @@ describe("install / update / icons", () => {
     const notInstalled = await request("POST", "/api/ai-tools/codex/update");
     assert.equal(notInstalled.status, 409);
     assert.equal(notInstalled.body.error.code, "ENOTINSTALLED");
-    // gemini was put on PATH by the refresh test, outside any npm prefix.
-    const notNpm = await request("POST", "/api/ai-tools/gemini/update");
+    // opencode was put on PATH by the refresh test, outside any npm prefix.
+    const notNpm = await request("POST", "/api/ai-tools/opencode/update");
     assert.equal(notNpm.status, 409);
     assert.equal(notNpm.body.error.code, "ENOTNPM");
     const cross = await request("POST", "/api/ai-tools/copilot/install", undefined, {
@@ -241,7 +241,7 @@ describe("install / update / icons", () => {
     assert.deepEqual(spawned.at(-1), [path.join(BIN, "claude"), "update"]);
     const v = await request("GET", "/api/ai-tools/versions");
     assert.equal(v.status, 200);
-    assert.equal(v.body.gemini.npmManaged, false);
+    assert.equal(v.body.opencode.npmManaged, false);
   });
 
   it("update-all answers ENOTHING when nothing has an update", async () => {