sync: ingestion improvements from private repo

- Fixed dimension auto-assignment (locked dimensions now properly assigned)
- Added description field as grounding context for AI
- Updated embedding format: Title → Description → Content → Dimensions
- Description-weighted search (5x boost)
- Bug fixes: extraction tool dimension display, DimensionSearchModal closing
- Removed quickLink tool (use Quick Link workflow instead)
- Added regenerate-description API endpoint

src/services/database/descriptionService.ts

@@ -0,0 +1,88 @@
+import { openai as openaiProvider } from '@ai-sdk/openai';
+import { generateText } from 'ai';
+
+export interface DescriptionInput {
+  title: string;
+  content?: string;
+  metadata?: {
+    source?: string;
+    channel_name?: string;
+    author?: string;
+    site_name?: string;
+  };
+  type?: string;
+}
+
+/**
+ * Generate a 280-character description for a knowledge node.
+ * The description starts with "This is a..." and identifies the content type.
+ */
+export async function generateDescription(input: DescriptionInput): Promise<string> {
+  try {
+    const prompt = buildDescriptionPrompt(input);
+
+    console.log(`[DescriptionService] Generating description for: "${input.title}"`);
+
+    const response = await generateText({
+      model: openaiProvider('gpt-4o-mini'),
+      prompt,
+      maxOutputTokens: 100,
+      temperature: 0.3,
+    });
+
+    const description = response.text.trim();
+
+    // Ensure it starts with "This is a" and is within limit
+    const finalDescription = description.slice(0, 280);
+
+    console.log(`[DescriptionService] Generated: "${finalDescription}"`);
+
+    return finalDescription;
+  } catch (error) {
+    console.error('[DescriptionService] Error generating description:', error);
+    // Return a fallback description
+    return `This is a ${input.type || 'knowledge item'} titled "${input.title.slice(0, 200)}".`;
+  }
+}
+
+function buildDescriptionPrompt(input: DescriptionInput): string {
+  const metadataLines: string[] = [];
+
+  if (input.metadata?.source) {
+    metadataLines.push(`Source: ${input.metadata.source}`);
+  }
+  if (input.metadata?.channel_name) {
+    metadataLines.push(`Channel: ${input.metadata.channel_name}`);
+  }
+  if (input.metadata?.author) {
+    metadataLines.push(`Author: ${input.metadata.author}`);
+  }
+  if (input.metadata?.site_name) {
+    metadataLines.push(`Site: ${input.metadata.site_name}`);
+  }
+  if (input.type) {
+    metadataLines.push(`Type: ${input.type}`);
+  }
+
+  const contentPreview = input.content?.slice(0, 500) || '';
+
+  return `Generate a concise description (max 280 characters) for this knowledge item.
+
+CRITICAL REQUIREMENTS:
+- Start with "This is a..."
+- Identify the content type (article, video, paper, podcast episode, tweet, book, tutorial, etc.)
+- Be specific about what the content covers
+- Maximum 280 characters total
+
+=== KNOWLEDGE ITEM ===
+Title: ${input.title}
+${metadataLines.length > 0 ? metadataLines.join('\n') : ''}
+${contentPreview ? `\nContent preview: ${contentPreview}${input.content && input.content.length > 500 ? '...' : ''}` : ''}
+
+=== YOUR RESPONSE ===
+Write ONLY the description, nothing else. Start with "This is a..."`;
+}
+
+export const descriptionService = {
+  generateDescription
+};