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/watcher.py

@@ -19,11 +19,11 @@ from ..database.engine import get_engine
 from ..database.models import (
     EventLog,
     NotificationTarget,
+    NotificationTracker,
+    NotificationTrackerState,
+    NotificationTrackerTarget,
     ServiceProvider,
     TemplateConfig,
-    Tracker,
-    TrackerState,
-    TrackerTarget,
     TrackingConfig,
 )
 
@@ -89,7 +89,7 @@ async def check_tracker(tracker_id: int) -> dict[str, Any]:
 
     # Load all DB data eagerly before entering aiohttp context
     async with AsyncSession(engine) as session:
-        tracker = await session.get(Tracker, tracker_id)
+        tracker = await session.get(NotificationTracker, tracker_id)
         if not tracker or not tracker.enabled:
             return {"status": "skipped", "reason": "disabled or not found"}
 
@@ -99,7 +99,7 @@ async def check_tracker(tracker_id: int) -> dict[str, Any]:
 
         # Load tracker state
         result = await session.exec(
-            select(TrackerState).where(TrackerState.tracker_id == tracker_id)
+            select(NotificationTrackerState).where(NotificationTrackerState.tracker_id == tracker_id)
         )
         states = result.all()
         state_dict: dict[str, Any] = {}
@@ -113,7 +113,7 @@ async def check_tracker(tracker_id: int) -> dict[str, Any]:
 
         # Load tracker-target links (replaces old target_ids JSON array)
         tt_result = await session.exec(
-            select(TrackerTarget).where(TrackerTarget.tracker_id == tracker_id)
+            select(NotificationTrackerTarget).where(NotificationTrackerTarget.tracker_id == tracker_id)
         )
         tracker_targets = tt_result.all()
 
@@ -188,7 +188,7 @@ async def check_tracker(tracker_id: int) -> dict[str, Any]:
                 existing.shared = cstate.get("shared", False)
                 session.add(existing)
             else:
-                new_ts = TrackerState(
+                new_ts = NotificationTrackerState(
                     tracker_id=tracker_id,
                     collection_id=cid,
                     collection_name=cstate.get("name", ""),