Bundle FastAPI backend into Next.js Docker container

The Next.js app was proxying /api/* to the old Flask/FastAPI server
at legal-ai.nautilus.marcusgroup.org. When that server went down,
the Next.js app's API calls failed with 503.

Now both services run in the same container:
- FastAPI (uvicorn) on :8000 — the API backend
- Next.js (node) on :3000 — proxies /api/* to localhost:8000

Changes:
- Dockerfile: multi-stage build with Python 3.12 + Node.js
- next.config.ts: default proxy target is now 127.0.0.1:8000
- start.sh: launches uvicorn in background + node in foreground
- pyproject.toml: add fastapi + uvicorn as explicit deps

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -1,21 +1,20 @@
 # ══════════════════════════════════════════════════════════════
-# Dockerfile — Next.js 16 web-ui (ui-rewrite branch only)
+# Dockerfile — Next.js frontend + FastAPI backend (single container)
 #
-# This file REPLACES the FastAPI Dockerfile on this branch so that
-# Coolify's default /Dockerfile lookup builds the new Next.js staging
-# UI. The FastAPI Dockerfile lives on `main` and is unaffected.
+# The container runs both:
+#   - FastAPI (uvicorn) on :8000  — the API backend
+#   - Next.js (node)    on :3000  — the frontend (proxies /api/* to :8000)
 #
-# When the rewrite is merged to main, decide between:
-#   (a) keeping both via separate Dockerfiles + dockerfile_location config, or
-#   (b) a multi-stage Dockerfile that serves both, or
-#   (c) fully replacing FastAPI's StaticFiles with this Next.js front end.
+# start.sh launches both processes.
 # ══════════════════════════════════════════════════════════════
 
+# ── Stage 1: Node deps ────────────────────────────────────────
 FROM node:20-alpine AS deps
 WORKDIR /app
 COPY web-ui/package.json web-ui/package-lock.json ./
 RUN npm ci --no-audit --no-fund
 
+# ── Stage 2: Build Next.js ────────────────────────────────────
 FROM node:20-alpine AS builder
 WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
@@ -23,18 +22,44 @@ COPY web-ui/ ./
 ENV NEXT_TELEMETRY_DISABLED=1
 RUN npm run build
 
-FROM node:20-alpine AS runner
+# ── Stage 3: Install Python deps ─────────────────────────────
+FROM python:3.12-alpine AS pydeps
+WORKDIR /opt/api
+COPY mcp-server/ ./mcp-server/
+RUN pip install --no-cache-dir ./mcp-server
+
+# ── Stage 4: Runner ───────────────────────────────────────────
+FROM python:3.12-alpine AS runner
 WORKDIR /app
+
+# Install Node.js (needed for Next.js standalone server)
+RUN apk add --no-cache nodejs
+
 ENV NODE_ENV=production
 ENV NEXT_TELEMETRY_DISABLED=1
 ENV PORT=3000
 ENV HOSTNAME=0.0.0.0
 
-# next.config.ts uses output: 'standalone', so we copy only the minimal runtime
+# Copy Python packages from pydeps stage
+COPY --from=pydeps /usr/local/lib/python3.12/site-packages /usr/local/lib/python3.12/site-packages
+COPY --from=pydeps /usr/local/bin/uvicorn /usr/local/bin/uvicorn
+
+# Copy Next.js standalone build
 COPY --from=builder /app/public ./public
 COPY --from=builder /app/.next/standalone ./
 COPY --from=builder /app/.next/static ./.next/static
 
+# Copy FastAPI backend code
+COPY web/ ./web/
+COPY mcp-server/src/ ./mcp-server/src/
+
+# Make mcp-server source available to web/app.py (it does sys.path.insert for legal_mcp)
+ENV PYTHONPATH=/app/mcp-server/src
+
+# Copy startup script
+COPY start.sh ./start.sh
+RUN chmod +x ./start.sh
+
 EXPOSE 3000
 
-CMD ["node", "server.js"]
+CMD ["./start.sh"]