Add an MCP server for the API, deployable next to the application

mcp/ exposes both APIs as MCP tools, one per operation in openapi.yaml,
named after the Laravel route each lands on (public_projects_index,
admin_pages_update, ...). Nothing is written by hand: the tools are
derived from the document the target application serves, which the
contract tests already hold to the truth.

Two transports over one core:

- stdio (`node mcp/server.mjs`), registered in .mcp.json, signing in
  with credentials from the environment and refreshing the token.
- Streamable HTTP (`--http`), stateless, deployed as the landing-mcp
  service. It holds no credentials: each request brings its caller's
  Pireon Basic credentials or bearer token, so the API applies that
  person's permissions. Sessions live in memory keyed by a hash,
  refused credentials are remembered for a minute, and the spec is
  reloaded every minute so new endpoints appear without a redeploy.

Left out on purpose: the token exchange, telemetry, and the contact and
apply forms, which notify real people. The preview secret is never sent
for anonymous callers, and is unset in the deployment by default.

A CI job runs the Node tests, including the HTTP mode end to end
against a fake application.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mcp/Dockerfile

@@ -0,0 +1,26 @@
+# syntax=docker/dockerfile:1
+
+###############################################################################
+# The MCP server, over HTTP. Its own image rather than a fourth command in the
+# PHP one: it shares no code with the application, only the API between them,
+# and Node is a runtime that image has no other reason to carry.
+###############################################################################
+FROM node:22-alpine
+
+WORKDIR /app
+
+ENV NODE_ENV=production \
+    LANDING_MCP_HOST=0.0.0.0 \
+    LANDING_MCP_PORT=3000
+
+COPY package.json package-lock.json ./
+RUN npm ci --omit=dev && npm cache clean --force
+
+COPY server.mjs ./
+COPY src ./src
+
+USER node
+
+EXPOSE 3000
+
+CMD ["node", "server.mjs", "--http"]