Add initial MCP version with SDK imports

[tysonthomas9]

Summary by CodeRabbit

• New Features

  • MCP tooling integrated into AI Chat: discovery, router/meta/all modes, per‑turn caps, autostart, allowlisting, dynamic per‑turn tool selection, meta‑tools for search/invoke, and sanitized tool-name/function mapping.

• UI

  • Settings: full MCP section (enable, endpoint/token, status, connect/refresh/disconnect, mode, caps, per‑tool allowlist); chat: lane‑based timeline for agent tool calls, tool details expanded by default, floating input bar, help opens external docs, beta warning.

• Tests

  • New unit/integration tests covering MCP SDK, registry, selection, meta‑tools, tool-name sanitization, and result filtering.

• Chores

  • Bundled MCP SDK and added license/README assets.