feat(session): query enabled sources before providers (#85)

UserSessionManager now queries the user_sources table for enabled
sources before calling any provider. Providers receive the per-user
JSON config directly instead of querying the DB themselves, removing
their db dependency and eliminating redundant round-trips.

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

apps/aelis-backend/src/session/user-session.ts

@@ -1,7 +1,6 @@
 import { FeedEngine, type FeedItem, type FeedResult, type FeedSource } from "@aelis/core"
 
 import type { FeedEnhancer } from "../enhancement/enhance-feed.ts"
-import type { FeedSourceProvider } from "./feed-source-provider.ts"
 
 export class UserSession {
 	readonly userId: string
@@ -70,25 +69,8 @@ export class UserSession {
 		return this.sources.get(sourceId) as T | undefined
 	}
 
-	/**
-	 * Re-resolves a source from its provider using this session's userId.
-	 * The source must already be registered. Throws if it isn't.
-	 * If the provider fails, the existing source is kept.
-	 */
-	async refreshSource(provider: FeedSourceProvider): Promise<void> {
-		if (!this.sources.has(provider.sourceId)) {
-			throw new Error(`Cannot refresh source "${provider.sourceId}": not registered`)
-		}
-
-		try {
-			const newSource = await provider.feedSourceForUser(this.userId)
-			this.replaceSource(provider.sourceId, newSource)
-		} catch (err) {
-			console.error(
-				`[UserSession] refreshSource("${provider.sourceId}") failed for user ${this.userId}:`,
-				err,
-			)
-		}
+	hasSource(sourceId: string): boolean {
+		return this.sources.has(sourceId)
 	}
 
 	/**