fix(mcp): import MCP handler statically so the prod build emits it

[vigneshrajsb]

Summary

Fixes the prod boot crash for the MCP server merged in #224. With MCP_SERVER_ENABLED=true, lifecycle-web pods crashloop at startup:

Error: Cannot find module './src/server/mcp/handler'
    at Object.<anonymous> (/app/.next/ws-server.js:87:28)

Root cause

ws-server.ts loaded the MCP handler via a deferred require('./src/server/mcp/handler'). Because that dynamic require is outside tsc's static import graph, tsc -p tsconfig.server.json never compiled the module into .next/ — so at boot the require of the never-emitted handler.js throws. (Local dev via ts-node and jest imports from src both resolve it, so only the prod build + MCP_SERVER_ENABLED=true exposed it.)

Why the deferred require is no longer needed

It existed solely to keep the ESM-only jose / MCP SDK off the boot path on Node < 20.19 (which can't require() ESM). That was a real concern when the MCP alphas shipped on node:20-slim — but #223 moved every build to node:22-slim before this code reached main. Since the Docker image welds the Node runtime to the app code, there is no artifact combining "MCP code + Node 20": old Node-20 images predate MCP entirely, and every MCP-carrying image is Node 22 (where require(esm) works). The workaround guards a state that can't occur.

Fix

Import the handler statically. tsc traces it through ws-server.ts's import graph and emits it normally, removing the build-vs-runtime gap at the root — no tsconfig.server.json include entry or build-time guard needed. The MCP_SERVER_ENABLED flag still gates whether the handler is wired up; only the module load moves to boot (a plain require on Node 22). Worker / MCP-off pods now load jose+SDK at boot too — negligible on Node 22.

Validation

• tsc -p tsconfig.server.json now emits .next/src/server/mcp/handler.js (+ auth.js, server.js, truncate.js) via the static graph; confirmed absent before this change, reproducing the crash.
• Server typecheck (tsconfig.server.json) exit 0; pnpm run lint clean; MCP unit tests match main baseline (build/boot-path change, no test impact).

Deploy: once merged, cut a fresh alpha from main and roll lifecycle-web — the prod realm and web env (MCP_SERVER_ENABLED, MCP_RESOURCE_URL) are already in place.