#101 Add MCP server and tool health manager

Summary\n- add a read-only MCP health API that detects Codex MCP config files for the active workspace\n- show configured servers, command paths, args, env requirements, and command/env health without launching servers\n- add a chat header MCP tools panel with copyable filesystem, git, memory, and fetch setup snippets\n- redact secret-like command arguments and avoid returning env values to the UI\n\n## Testing\n- pnpm -C apps/codex-claw lint\n- pnpm -C apps/codex-claw build\n- pnpm -C apps/codex-claw test\n\nCloses #88

---

Summary by cubic

Adds a read-only MCP health API and a chat header “MCP tools” panel to inspect configured servers, command paths, args, and env requirements without launching servers. Includes copyable setup snippets for filesystem, git, memory, and fetch, with secrets redacted.

• New Features
  • API: GET /api/mcp-health scans Codex config candidates and returns server health (ok/warning/error), resolved command paths, redacted args, env requirement status, checked paths, and timestamp.
  • UI: New “MCP tools” panel in the chat header lets you view server status, summaries, resolved paths, and copy the command; shows the detected config path and supports refresh.
  • Setup snippets: Copyable examples for filesystem, git, memory, and fetch, prefilled with the active workspace path.
  • Safety: Secret-like CLI args are redacted and env values are never returned—only their presence/need is reported.