feat: add Docker deployment (Dockerfile, compose, Caddyfile)

Multi-stage Dockerfile builds SvelteKit then runs a lean production image. docker-compose.yml wires up MariaDB with health checks, the app, and Caddy for TLS termination. Caddyfile uses SITE_DOMAIN env var with localhost fallback.

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

Caddyfile

@@ -0,0 +1,3 @@
+{$SITE_DOMAIN:localhost} {
+	reverse_proxy app:3000
+}

Dockerfile

@@ -0,0 +1,18 @@
+FROM node:22-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm ci
+COPY . .
+RUN npm run build
+
+FROM node:22-alpine
+WORKDIR /app
+COPY --from=builder /app/build ./build
+COPY --from=builder /app/node_modules ./node_modules
+COPY --from=builder /app/package.json ./
+COPY --from=builder /app/drizzle ./drizzle
+COPY --from=builder /app/scripts ./scripts
+
+ENV NODE_ENV=production
+EXPOSE 3000
+CMD ["node", "build"]

docker-compose.yml

@@ -0,0 +1,52 @@
+services:
+  db:
+    image: mariadb:11
+    restart: unless-stopped
+    environment:
+      MYSQL_ROOT_PASSWORD: ${DB_ROOT_PASSWORD:-fosterflow}
+      MYSQL_DATABASE: fosterflow
+      MYSQL_USER: fosterflow
+      MYSQL_PASSWORD: ${DB_PASSWORD:-fosterflow}
+    volumes:
+      - db_data:/var/lib/mysql
+    healthcheck:
+      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  app:
+    build: .
+    restart: unless-stopped
+    depends_on:
+      db:
+        condition: service_healthy
+    environment:
+      DATABASE_URL: mysql://fosterflow:${DB_PASSWORD:-fosterflow}@db:3306/fosterflow
+      SESSION_SECRET: ${SESSION_SECRET:-change-me-in-production}
+      PUBLIC_SITE_URL: ${PUBLIC_SITE_URL:-http://localhost:3000}
+      UPLOAD_DIR: /app/uploads
+      PORT: 3000
+    env_file:
+      - .env
+    ports:
+      - "3000:3000"
+    volumes:
+      - uploads:/app/uploads
+
+  caddy:
+    image: caddy:2-alpine
+    restart: unless-stopped
+    ports:
+      - "80:80"
+      - "443:443"
+    volumes:
+      - ./Caddyfile:/etc/caddy/Caddyfile
+      - caddy_data:/data
+      - caddy_config:/config
+
+volumes:
+  db_data:
+  uploads:
+  caddy_data:
+  caddy_config: