feat: Add Docker infrastructure with Caddy and startup scripts (#25, #26)

Issue #25 - Docker multi-service infrastructure:
- Create docker/Dockerfile with multi-stage build, git support, port 8080
- Create docker/docker-compose.yml with app + Caddy services
- Create docker/Caddyfile for HTTPS termination and reverse proxy
- Create docker/.env.example with configuration template

Issue #26 - Startup scripts and tests:
- Create scripts/start.sh for production startup with env validation
- Create scripts/healthcheck.sh for Docker health checks
- Add health endpoint tests to test_mcp_endpoints.py
- Fix middleware order (HealthCheckBypass must wrap BearerAuth)
- Fix pyproject.toml testpaths to use 'tests' directory
- Update test_config.py for new defaults (0.0.0.0:8080)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker/Dockerfile

@@ -0,0 +1,65 @@
+# Gitea MCP Remote — Dockerfile
+# Multi-stage build for optimized image size
+
+FROM python:3.11-slim as builder
+
+# Set working directory
+WORKDIR /build
+
+# Install build dependencies including git for marketplace dependency
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    gcc \
+    git \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy requirements first for better caching
+COPY requirements.txt .
+RUN pip install --user --no-cache-dir -r requirements.txt
+
+# Copy source code
+COPY pyproject.toml .
+COPY src/ src/
+
+# Install package (includes marketplace dependency from git)
+RUN pip install --user --no-cache-dir .
+
+# Production stage
+FROM python:3.11-slim
+
+# Install runtime dependencies
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+    curl \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set working directory
+WORKDIR /app
+
+# Copy installed packages from builder
+COPY --from=builder /root/.local /root/.local
+
+# Copy source code
+COPY src/ src/
+COPY pyproject.toml .
+
+# Make sure scripts in .local are usable
+ENV PATH=/root/.local/bin:$PATH
+
+# Set Python environment variables
+ENV PYTHONUNBUFFERED=1
+ENV PYTHONDONTWRITEBYTECODE=1
+
+# Default to port 8080 (Caddy proxies to this)
+ENV HTTP_PORT=8080
+ENV HTTP_HOST=0.0.0.0
+
+# Expose port
+EXPOSE 8080
+
+# Health check using curl
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD curl -f http://localhost:8080/health || exit 1
+
+# Run the MCP server
+CMD ["gitea-mcp-remote"]