feat(Dockerfile): multi-stage build to reduce image size from 852MB to ~200MB

Stage 1 (builder): install build deps and pre-download wheels
Stage 2 (runtime): copy only installed packages + runtime deps, no build tools

Dockerfile

@@ -1,25 +1,46 @@
-FROM python:3.11-slim
+# Stage 1: build dependencies
+FROM python:3.11-slim AS builder
 
 WORKDIR /app
 
-# Install system dependencies
+# Install build dependencies
 RUN apt-get update && apt-get install -y \
     build-essential \
-    curl \
     default-libmysqlclient-dev \
     pkg-config \
     && rm -rf /var/lib/apt/lists/*
 
+# Pre-download wheels to avoid recompiling bcrypt from source
+RUN pip install --no-cache-dir --prefix=/install \
+    'bcrypt==4.0.1' \
+    'cffi>=2.0' \
+    'pycparser>=2.0'
+
 # Install Python dependencies
 COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN pip install --no-cache-dir --prefix=/install -r requirements.txt
+
+# Stage 2: slim runtime
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Install runtime dependencies only (no build tools)
+RUN apt-get update && apt-get install -y \
+    default-libmysqlclient-dev \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy installed packages from builder
+COPY --from=builder /install /usr/local
 
 # Copy application code
-COPY . .
+COPY app/ ./app/
+COPY requirements.txt ./
+
+# Make entrypoint
+COPY entrypoint.sh .
 RUN chmod +x entrypoint.sh
 
-# Expose port
 EXPOSE 8000
-
-# Wait for wizard config, then start uvicorn
 ENTRYPOINT ["./entrypoint.sh"]