feat: add feature enable/disable flags for notification platforms

- Add MATTERMOST_ENABLED, TELEGRAM_ENABLED, SYNOLOGY_ENABLED, NOTION_ENABLED, GA4_ENABLED flags
- Skip disabled platforms in message_sender.py
- Comment out unused config variables in .env.sample
- Add .vscode settings for virtual environment debugging

core/config.py

@@ -126,6 +126,7 @@ class Config:
         
         # GA4 설정
         self.ga4 = {
+            'enabled': self._get_bool('GA4_ENABLED', False),
             'api_token': self._get_env('GA4_API_TOKEN', ''),
             'property_id': self._get_int('GA4_PROPERTY_ID', 0),
             'service_account_file': self._get_env('GA4_SERVICE_ACCOUNT_FILE', './conf/service-account-credentials.json'),
@@ -183,6 +184,7 @@ class Config:
         
         # Mattermost 설정
         self.mattermost = {
+            'enabled': self._get_bool('MATTERMOST_ENABLED', False),
             'url': self._get_env('MATTERMOST_URL', ''),
             'token': self._get_env('MATTERMOST_TOKEN', ''),
             'channel_id': self._get_env('MATTERMOST_CHANNEL_ID', ''),
@@ -191,18 +193,21 @@ class Config:
         
         # Telegram 설정
         self.telegram = {
+            'enabled': self._get_bool('TELEGRAM_ENABLED', False),
             'bot_token': self._get_env('TELEGRAM_BOT_TOKEN', ''),
             'chat_id': self._get_env('TELEGRAM_CHAT_ID', ''),
         }
         
         # Synology Chat 설정
         self.synology = {
+            'enabled': self._get_bool('SYNOLOGY_ENABLED', False),
             'chat_url': self._get_env('SYNOLOGY_CHAT_URL', ''),
             'chat_token': self._get_env('SYNOLOGY_CHAT_TOKEN', ''),
         }
         
         # Notion 설정
         self.notion = {
+            'enabled': self._get_bool('NOTION_ENABLED', False),
             'api_secret': self._get_env('NOTION_API_SECRET', ''),
         }