feat: add MCP server for AI agent integration

Adds a Streamable HTTP MCP server at /mcp that exposes 19 tools
covering rundown entries, rundown management, runtime state, project
info, automations, and custom fields. Includes Bearer token auth
support and a UI card in Settings > Sharing showing the endpoint URL
and Claude Desktop config.

https://claude.ai/code/session_01U24MeuUacYXeQhbX3tatEe

apps/server/package.json

@@ -6,6 +6,7 @@
   "exports": "./src/index.js",
   "dependencies": {
     "@googleapis/sheets": "^5.0.5",
+    "@modelcontextprotocol/sdk": "^1.15.0",
     "cookie": "1.0.2",
     "cookie-parser": "1.4.7",
     "cors": "2.8.6",