feat: entity relationship refactor — notification trackers, command system, chat actions

Rework entity schema: rename Tracker→NotificationTracker, add CommandConfig/
CommandTracker/CommandTrackerListener entities for decoupled command handling.
Commands now resolve through CommandTracker→CommandConfig instead of
TelegramBot.commands_config. Smart ref-counted bot polling based on active
listeners. Add chat_action to telegram targets. Full frontend CRUD pages
for command configs and command trackers. Idempotent SQLite migrations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/server/src/notify_bridge_server/services/scheduler.py

@@ -26,9 +26,9 @@ async def start_scheduler() -> None:
 
     await _load_tracker_jobs()
 
-    # Start Telegram bot polling for bots in polling mode
-    from .telegram_poller import start_bot_polling
-    await start_bot_polling()
+    # Start Telegram bot polling for bots with active command listeners
+    from .telegram_poller import start_command_listener_polling
+    await start_command_listener_polling()
 
 
 async def _load_tracker_jobs() -> None:
@@ -36,13 +36,13 @@ async def _load_tracker_jobs() -> None:
     from sqlmodel import select
     from sqlmodel.ext.asyncio.session import AsyncSession
     from ..database.engine import get_engine
-    from ..database.models import Tracker
+    from ..database.models import NotificationTracker
 
     engine = get_engine()
     scheduler = get_scheduler()
 
     async with AsyncSession(engine) as session:
-        result = await session.exec(select(Tracker).where(Tracker.enabled == True))
+        result = await session.exec(select(NotificationTracker).where(NotificationTracker.enabled == True))
         trackers = result.all()
 
     for tracker in trackers: