feat: locale-aware command templates, debounced auto-sync, entity pickers

- Locale-aware templates: CommandTemplateSlot now has a locale column,
  allowing each slot to have per-language variants (EN/RU). Templates
  are resolved at runtime from the Telegram user's language_code.

- Merged system configs: "Default Commands (EN)" and "(RU)" merged
  into a single "Default Commands" config with locale-aware slots.
  Migration handles existing data automatically.

- Configurable command descriptions: hardcoded COMMAND_DESCRIPTIONS
  replaced with desc_* template slots (desc_status, desc_help, etc.)
  that users can customize per locale. setMyCommands registers all
  locales explicitly.

- Removed locale from CommandConfig: no longer needed since locale
  is derived from the Telegram user's language at runtime.

- Debounced command auto-sync: after command config/tracker changes,
  affected bots are marked dirty and synced after a 30s debounce
  window. Manual "Sync with Telegram" button still works.

- Entity pickers in LinkedTargetsSection: replaced 6 plain <select>
  elements with EntitySelect components (search, icons, keyboard nav).
  Added onselect callback and size="sm" props to EntitySelect.

packages/server/src/notify_bridge_server/main.py

@@ -39,7 +39,7 @@ async def lifespan(app: FastAPI):
     await init_db()
     # Run data migrations (idempotent)
     from .database.engine import get_engine
-    from .database.migrations import migrate_schema, migrate_tracker_targets, migrate_entity_refactor, migrate_template_slots, migrate_target_receivers, migrate_template_locale, migrate_receivers_from_config
+    from .database.migrations import migrate_schema, migrate_tracker_targets, migrate_entity_refactor, migrate_template_slots, migrate_target_receivers, migrate_template_locale, migrate_receivers_from_config, migrate_command_slot_locale
     engine = get_engine()
     await migrate_schema(engine)
     await migrate_tracker_targets(engine)
@@ -48,6 +48,7 @@ async def lifespan(app: FastAPI):
     await migrate_target_receivers(engine)
     await migrate_template_locale(engine)
     await migrate_receivers_from_config(engine)
+    await migrate_command_slot_locale(engine)
     await _seed_default_templates()
     await _seed_default_command_templates()
     # Configure webhook secret from DB setting (falls back to env var)
@@ -196,7 +197,11 @@ async def _seed_default_templates():
 
 
 async def _seed_default_command_templates():
-    """Seed or update default command response templates on startup."""
+    """Seed or update default command response templates on startup.
+
+    Creates a single 'Default Commands' config with locale-aware slots
+    (each slot has an EN and RU version stored as separate rows).
+    """
     from sqlmodel import func, select
     from sqlmodel.ext.asyncio.session import AsyncSession
     from .database.engine import get_engine
@@ -205,59 +210,49 @@ async def _seed_default_command_templates():
 
     engine = get_engine()
     async with AsyncSession(engine) as session:
-        result = await session.exec(select(func.count()).select_from(CommandTemplateConfig))
-        count = result.one()
+        # Find or create the system-owned config
+        result = await session.exec(
+            select(CommandTemplateConfig).where(CommandTemplateConfig.user_id == 0)
+        )
+        system_configs = result.all()
 
-        if count == 0:
-            # First startup — seed EN and RU defaults
-            for locale in ("en", "ru"):
-                slots = load_default_command_templates(locale)
-                if not slots:
-                    continue
-                name = f"Default Commands ({locale.upper()})"
-                config = CommandTemplateConfig(
-                    user_id=0,
-                    provider_type="immich",
-                    name=name,
-                    description=f"Default Immich command templates ({locale.upper()})",
-                    locale=locale,
+        if not system_configs:
+            # First startup — create single merged config
+            config = CommandTemplateConfig(
+                user_id=0,
+                provider_type="immich",
+                name="Default Commands",
+                description="Default Immich command templates",
+            )
+            session.add(config)
+            await session.flush()
+        else:
+            config = system_configs[0]
+
+        # Upsert slots for each locale
+        for locale in ("en", "ru"):
+            slots = load_default_command_templates(locale)
+            if not slots:
+                continue
+            for slot_name, template_text in slots.items():
+                slot_result = await session.exec(
+                    select(CommandTemplateSlot).where(
+                        CommandTemplateSlot.config_id == config.id,
+                        CommandTemplateSlot.slot_name == slot_name,
+                        CommandTemplateSlot.locale == locale,
+                    )
                 )
-                session.add(config)
-                await session.flush()
-                for slot_name, template_text in slots.items():
+                existing = slot_result.first()
+                if existing:
+                    existing.template = template_text
+                    session.add(existing)
+                else:
                     session.add(CommandTemplateSlot(
                         config_id=config.id,
                         slot_name=slot_name,
+                        locale=locale,
                         template=template_text,
                     ))
-        else:
-            # Update existing system-owned command templates from files
-            result = await session.exec(
-                select(CommandTemplateConfig).where(CommandTemplateConfig.user_id == 0)
-            )
-            system_configs = result.all()
-            for config in system_configs:
-                locale = config.locale if config.locale else ("ru" if "(RU)" in config.name else "en")
-                slots = load_default_command_templates(locale)
-                if not slots:
-                    continue
-                for slot_name, template_text in slots.items():
-                    slot_result = await session.exec(
-                        select(CommandTemplateSlot).where(
-                            CommandTemplateSlot.config_id == config.id,
-                            CommandTemplateSlot.slot_name == slot_name,
-                        )
-                    )
-                    existing = slot_result.first()
-                    if existing:
-                        existing.template = template_text
-                        session.add(existing)
-                    else:
-                        session.add(CommandTemplateSlot(
-                            config_id=config.id,
-                            slot_name=slot_name,
-                            template=template_text,
-                        ))
 
         await session.commit()