fix(#338): Add structured logging for embedding failures

- Replace console.error with NestJS Logger
- Include entry ID and workspace ID in error context
- Easier to track and debug embedding issues

Refs #338

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/knowledge/knowledge.service.ts

@@ -244,7 +244,11 @@ export class KnowledgeService {
 
     // Generate and store embedding asynchronously (don't block the response)
     this.generateEntryEmbedding(result.id, result.title, result.content).catch((error: unknown) => {
-      console.error(`Failed to generate embedding for entry ${result.id}:`, error);
+      this.logger.warn(`Failed to generate embedding for entry - embedding will be missing`, {
+        entryId: result.id,
+        workspaceId,
+        error: error instanceof Error ? error.message : String(error),
+      });
     });
 
     // Invalidate search and graph caches (new entry affects search results)
@@ -407,7 +411,11 @@ export class KnowledgeService {
     if (updateDto.content !== undefined || updateDto.title !== undefined) {
       this.generateEntryEmbedding(result.id, result.title, result.content).catch(
         (error: unknown) => {
-          console.error(`Failed to generate embedding for entry ${result.id}:`, error);
+          this.logger.warn(`Failed to generate embedding for entry - embedding will be missing`, {
+            entryId: result.id,
+            workspaceId,
+            error: error instanceof Error ? error.message : String(error),
+          });
         }
       );
     }