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/pages/AiToolConfig.tsx

@@ -27,7 +27,7 @@ import type { Lane } from "../lib/types";
 import { useAiTools } from "../hooks/useAiTools";
 import { AiToolIcon } from "../components/AiToolIcon";
 import { ModelPicker } from "../components/run/RunSetup";
-import { PricingSettings } from "../components/settings/PricingSettings";
+import { PricingLink } from "../components/settings/PricingSettings";
 import { AntigravityHooksSettings } from "../components/settings/AntigravityHooksSettings";
 
 /** Cards one tool adds below the generic ones. */
@@ -307,7 +307,7 @@ export function AiToolConfig({ toolId }: { toolId: string }) {
           <DefaultModel toolId={toolId} saved={tool.defaultModel ?? ""} />
         </Card>
       )}
-      {tool.modelVendor && <PricingSettings vendor={tool.modelVendor} id={`${toolId}-pricing`} />}
+      {tool.modelVendor && <PricingLink vendor={tool.modelVendor} />}
       {tool.configFiles > 0 && (
         <Card title={t("toolTab.config")} Icon={FileCog}>
           <ConfigFiles toolId={toolId} />