feat: add HTTP transport for Docker proxy support

Adds src/http-server.ts for Streamable HTTP transport, enabling the
law-mcp-proxy to route requests to this MCP via Docker network.

Endpoints: GET /health, POST /mcp, GET /mcp, DELETE /mcp

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Dockerfile

@@ -0,0 +1,26 @@
+# Auto-generated Dockerfile for Law MCP HTTP transport.
+# Built by rollout-http-transport.sh from Ansvar-Architecture-Documentation.
+
+# ── Stage 1: Build ──────────────────────────────────────────────────────
+FROM node:20-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci --ignore-scripts
+COPY tsconfig.json ./
+COPY src ./src
+RUN npm run build
+
+# ── Stage 2: Production ────────────────────────────────────────────────
+FROM node:20-alpine AS production
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci --omit=dev --ignore-scripts
+COPY --from=builder /app/dist ./dist
+COPY data/database.db ./data/database.db
+
+# Security: non-root user
+RUN addgroup -S nodejs && adduser -S nodejs -G nodejs
+USER nodejs
+
+ENV NODE_ENV=production
+CMD ["node", "dist/src/http-server.js"]