refactor(backend): rename feed dir to engine

Co-authored-by: Ona <no-reply@ona.com>

apps/aelis-backend/src/server.ts

@@ -5,7 +5,7 @@ import { registerAuthHandlers } from "./auth/http.ts"
 import { mockAuthSessionMiddleware, requireSession } from "./auth/session-middleware.ts"
 import { createFeedEnhancer } from "./enhancement/enhance-feed.ts"
 import { createLlmClient } from "./enhancement/llm-client.ts"
-import { registerFeedHttpHandlers } from "./feed/http.ts"
+import { registerFeedHttpHandlers } from "./engine/http.ts"
 import { registerLocationHttpHandlers } from "./location/http.ts"
 import { UserSessionManager } from "./session/index.ts"
 import { WeatherSourceProvider } from "./weather/provider.ts"