feat(ai-tools): drop OpenCode and Grok Build

- opencode.json / grok.json leave the built-in catalog; opencode-usage.js,
  its poller, transcript branch and table creation go with it (existing
  tables and session rows stay as history).
- A Grok payload reaching the Claude hook route (Grok runs the Claude hooks
  itself) is dropped instead of recorded as tool = 'grok'.
- quota.js no longer reads Grok or OpenCode Go logins.
- Redone on v2.8.22 from c6b2892 (feat/grok-usage, never merged).

client/src/components/lanes/__tests__/AddLaneModal.test.tsx

@@ -69,7 +69,7 @@ const TOOLS: AiToolsView = {
     tool("codex", "Codex", { launcher: "codex", proxyCapable: true, prompt: null }),
     tool("gemini", "Gemini"),
     tool("aider", "Aider", { installed: false, path: null }),
-    tool("grok", "Grok", { enabled: false }),
+    tool("goose", "Goose", { enabled: false }),
   ],
 };