refactor: modularize project structure and separate API from crawlers

- Introduce app/ package with config, services (storage, notifications), API server, and crawler modules
- Add BaseCrawler and BarronsCrawler; extract notifications and storage
- Keep enhanced_crawler.py as back-compat entry delegating to app.runner
- Add template crawler for future sites
- Update README with new structure and usage
- Extend .env.template with DATA_DIR/LOG_DIR options

app/crawlers/base.py

@@ -0,0 +1,136 @@
+from __future__ import annotations
+
+import hashlib
+import time
+import signal
+from abc import ABC, abstractmethod
+from datetime import datetime
+from typing import List, Dict, Optional
+
+import schedule
+
+from app.config import AppConfig
+from app.services import storage
+from app.services import notifications as notif
+
+
+class BaseCrawler(ABC):
+    def __init__(self, name: str, config: AppConfig, logger, data_filename: str):
+        self.name = name
+        self.config = config
+        self.logger = logger
+        self.data_path = storage.data_file_path(config.data_dir, data_filename)
+
+        self.running = True
+        self._first_check_done = False
+
+        self.stats = {
+            'start_time': datetime.now().isoformat(),
+            'total_checks': 0,
+            'new_picks_found': 0,
+            'last_check': None,
+            'last_notification': None,
+            'errors': 0,
+        }
+
+    # --- Abstract site-specific hooks ---
+    @abstractmethod
+    def fetch_page(self) -> Optional[str]:
+        ...
+
+    @abstractmethod
+    def parse_items(self, html_content: str) -> List[Dict]:
+        ...
+
+    # --- Generic helpers ---
+    def find_new(self, current: List[Dict], previous: List[Dict]) -> List[Dict]:
+        prev_hashes = {p.get('hash') for p in previous if 'hash' in p}
+        return [p for p in current if p.get('hash') not in prev_hashes]
+
+    # --- Main check ---
+    def run_check(self) -> Optional[List[Dict]]:
+        self.logger.info(f"開始檢查 {self.name}...")
+        self.stats['total_checks'] += 1
+        self.stats['last_check'] = datetime.now().isoformat()
+        try:
+            html = self.fetch_page()
+            if not html:
+                return []
+            current = self.parse_items(html)
+            if not current:
+                self.logger.warning("未找到內容")
+                return []
+
+            prev = storage.load_json(self.data_path).get('stock_picks', [])
+            new_items = self.find_new(current, prev)
+
+            if new_items:
+                self.logger.info(f"🚨 發現 {len(new_items)} 條新內容")
+                self.stats['new_picks_found'] += len(new_items)
+                self._send_notifications(new_items)
+                storage.save_json(self.data_path, {
+                    'last_update': datetime.now().isoformat(),
+                    'stock_picks': current,
+                    'stats': self.stats,
+                })
+                return new_items
+
+            # Optionally notify on first run
+            if (not self._first_check_done) and self.config.always_notify_on_startup and current:
+                self.logger.info("🟢 啟動首次檢查：無新內容，但依設定寄出目前清單")
+                self._send_notifications(current)
+                storage.save_json(self.data_path, {
+                    'last_update': datetime.now().isoformat(),
+                    'stock_picks': current,
+                    'stats': self.stats,
+                })
+                return current
+
+            self.logger.info("✅ 沒有發現新內容")
+            return []
+        except Exception as e:
+            self.logger.error(f"檢查過程錯誤: {e}")
+            self.stats['errors'] += 1
+            return None
+
+    def _send_notifications(self, items: List[Dict]) -> None:
+        sent = False
+        if self.config.email:
+            try:
+                notif.send_email(items, self.config.email)
+                sent = True
+            except Exception as e:
+                self.logger.error(f"電子郵件通知失敗: {e}")
+        if self.config.webhook_url:
+            try:
+                notif.send_webhook(items, self.config.webhook_url)
+                sent = True
+            except Exception as e:
+                self.logger.error(f"Webhook 通知失敗: {e}")
+        if self.config.discord_webhook:
+            try:
+                notif.send_discord(items, self.config.discord_webhook)
+                sent = True
+            except Exception as e:
+                self.logger.error(f"Discord 通知失敗: {e}")
+        if sent:
+            self.stats['last_notification'] = datetime.now().isoformat()
+
+    # --- Run loop ---
+    def _signal_handler(self, signum, frame):
+        self.logger.info("收到停止信號，正在關閉...")
+        self.running = False
+
+    def run(self):
+        signal.signal(signal.SIGINT, self._signal_handler)
+        signal.signal(signal.SIGTERM, self._signal_handler)
+
+        schedule.every(self.config.check_interval).seconds.do(self.run_check)
+        self.logger.info(f"🚀 爬蟲已啟動，每 {self.config.check_interval} 秒檢查一次")
+        self.run_check()
+        self._first_check_done = True
+        while self.running:
+            schedule.run_pending()
+            time.sleep(1)
+        self.logger.info("爬蟲已停止")
+