feat(cli): make executor mcp ensure a durable daemon and bridge to it

executor mcp no longer starts a server in-process. It ensures a durable
detached daemon and bridges stdio JSON-RPC to that owner over HTTP.
Concurrent cold starts run a race-safe election: one process becomes the
owner and the rest wait for its manifest and attach instead of failing.
The owner's lifetime is independent of any MCP client, so many clients,
the web UI, and the desktop app share one local server.

This builds on the merged start-lock primitive so no client ever owns the
database, replacing the earlier approach where the first mcp process
started a server in-process and bridged to itself.

Adds a cold-start election probe across the cli VM targets plus a local
attach stress test; the one-winner, rest-attach behavior is verified on
macOS, Linux, and Windows.

Author: RhysSullivan

apps/cli/package.json

@@ -30,6 +30,7 @@
     "@executor-js/runtime-quickjs": "workspace:*",
     "@executor-js/sdk": "workspace:*",
     "@jitl/quickjs-wasmfile-release-sync": "catalog:",
+    "@modelcontextprotocol/sdk": "^1.29.0",
     "@sentry/bun": "^10.57.0",
     "effect": "catalog:",
     "quickjs-emscripten": "catalog:"