Add entity CRUD events over WebSocket with auto-refresh

Broadcast entity_changed and device_health_changed events via the event
bus so the frontend can auto-refresh cards without polling. Adds
exponential backoff on WS reconnect.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/api/routes/automations.py

@@ -6,6 +6,7 @@ from fastapi import APIRouter, Depends, HTTPException, Request
 
 from wled_controller.api.auth import AuthRequired
 from wled_controller.api.dependencies import (
+    fire_entity_event,
     get_automation_engine,
     get_automation_store,
     get_scene_preset_store,
@@ -174,6 +175,7 @@ async def create_automation(
     if automation.enabled:
         await engine.trigger_evaluate()
 
+    fire_entity_event("automation", "created", automation.id)
     return _automation_to_response(automation, engine, request)
 
 
@@ -273,6 +275,7 @@ async def update_automation(
     if automation.enabled:
         await engine.trigger_evaluate()
 
+    fire_entity_event("automation", "updated", automation_id)
     return _automation_to_response(automation, engine, request)
 
 
@@ -296,6 +299,8 @@ async def delete_automation(
     except ValueError as e:
         raise HTTPException(status_code=404, detail=str(e))
 
+    fire_entity_event("automation", "deleted", automation_id)
+
 
 # ===== Enable/Disable =====