feat(email): add SMTP security modes (starttls/ssl/none) with sensible default ports; add /notify_test endpoint; support ALWAYS_NOTIFY_ON_STARTUP to force first-run notification

chore(docker): run enhanced_crawler.py as entrypoint

ops(compose): load env via env_file and remove hardcoded secrets

docs: update README and .env.template for SMTP and startup notification

docker-compose.yml

@@ -6,24 +6,10 @@ services:
     build: .
     container_name: barrons-crawler
     restart: unless-stopped
-    environment:
-      # 爬蟲設定
-      - CHECK_INTERVAL=300  # 5分鐘
-      - LOG_LEVEL=INFO
-      
-      # 電子郵件設定（可選）
-      - EMAIL_SMTP_SERVER=smtp.gmail.com
-      - EMAIL_SMTP_PORT=587
-      - EMAIL_FROM=your_email@gmail.com
-      - EMAIL_TO=notification@gmail.com
-      - EMAIL_USERNAME=your_email@gmail.com
-      - EMAIL_PASSWORD=your_app_password
-      
-      # Webhook 設定（可選）
-      - WEBHOOK_URL=https://hooks.slack.com/services/YOUR/SLACK/WEBHOOK
-      
-      # Discord 設定（可選）
-      - DISCORD_WEBHOOK=https://discord.com/api/webhooks/YOUR/DISCORD/WEBHOOK
+    # 將同目錄的 .env 檔注入容器環境變數
+    env_file:
+      - .env
+    # 所有環境變數由 .env 提供
       
     volumes:
       - ./data:/app/data  # 資料持久化
@@ -47,4 +33,4 @@ services:
     command: redis-server --appendonly yes
 
 volumes:
-  redis_data:
+  redis_data: