migrate: replace Firebase with PostgreSQL across core routes

- chat-context.ts: session history now from fs_sessions
- /api/sessions: reads from fs_sessions (NextAuth session auth)
- /api/github/connect: NextAuth session + stores in fs_users.data
- /api/user/api-key: NextAuth session + stores in fs_users.data
- /api/projects/[id]/vision: PATCH to fs_projects JSONB
- /api/projects/[id]/knowledge/items: reads from fs_knowledge_items
- /api/projects/[id]/knowledge/import-ai-chat: uses pg createKnowledgeItem
- lib/server/knowledge.ts: fully rewritten to use PostgreSQL
- entrypoint.sh: add fs_knowledge_items and chat_conversations tables

Made-with: Cursor

app/api/projects/[projectId]/knowledge/items/route.ts

@@ -1,5 +1,7 @@
 import { NextResponse } from 'next/server';
-import { getAdminAuth, getAdminDb } from '@/lib/firebase/admin';
+import { getServerSession } from 'next-auth';
+import { authOptions } from '@/lib/auth/authOptions';
+import { query } from '@/lib/db-postgres';
 
 export async function GET(
   request: Request,
@@ -7,75 +9,30 @@ export async function GET(
 ) {
   try {
     const { projectId } = await params;
-    
-    // Authentication (skip in development if no auth header)
-    const authHeader = request.headers.get('Authorization');
-    const isDevelopment = process.env.NODE_ENV === 'development';
-    
-    if (!isDevelopment || authHeader?.startsWith('Bearer ')) {
-      if (!authHeader?.startsWith('Bearer ')) {
-        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
-      }
 
-      const token = authHeader.substring(7);
-      const auth = getAdminAuth();
-      const decoded = await auth.verifyIdToken(token);
-      
-      if (!decoded?.uid) {
-        return NextResponse.json({ error: 'Invalid token' }, { status: 401 });
-      }
+    const session = await getServerSession(authOptions);
+    if (!session?.user?.email) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
     }
 
-    // Fetch knowledge items from Firestore
-    console.log('[API /knowledge/items] Fetching items for project:', projectId);
-    
-    let items = [];
-    
-    try {
-      const adminDb = getAdminDb();
-      const knowledgeSnapshot = await adminDb
-        .collection('knowledge')
-        .where('projectId', '==', projectId)
-        .orderBy('createdAt', 'desc')
-        .limit(100)
-        .get();
-
-      console.log('[API /knowledge/items] Found', knowledgeSnapshot.size, 'items');
-
-      items = knowledgeSnapshot.docs.map(doc => {
-        const data = doc.data();
-        return {
-          id: doc.id,
-          title: data.title || data.content?.substring(0, 50) || 'Untitled',
-          sourceType: data.sourceType,
-          content: data.content,
-          sourceMeta: data.sourceMeta,
-          createdAt: data.createdAt?.toDate?.()?.toISOString() || data.createdAt,
-          updatedAt: data.updatedAt?.toDate?.()?.toISOString() || data.updatedAt,
-        };
-      });
-    } catch (firestoreError) {
-      console.error('[API /knowledge/items] Firestore query failed:', firestoreError);
-      console.error('[API /knowledge/items] This is likely due to missing Firebase Admin credentials or Firestore not being set up');
-      // Return empty array instead of failing - the UI will show "No chats yet" and "No images yet"
-      items = [];
-    }
-
-    return NextResponse.json({
-      success: true,
-      items,
-      count: items.length,
-    });
-  } catch (error) {
-    console.error('[API /knowledge/items] Error fetching knowledge items:', error);
-    console.error('[API /knowledge/items] Error stack:', error instanceof Error ? error.stack : 'No stack trace');
-    return NextResponse.json(
-      { 
-        error: 'Failed to fetch knowledge items',
-        details: error instanceof Error ? error.message : String(error)
-      },
-      { status: 500 }
+    const rows = await query<{ id: string; data: any; created_at: string; updated_at: string }>(
+      `SELECT id, data, created_at, updated_at FROM fs_knowledge_items WHERE project_id = $1 ORDER BY created_at DESC LIMIT 100`,
+      [projectId]
     );
+
+    const items = rows.map((row) => ({
+      id: row.id,
+      title: row.data?.title || row.data?.content?.substring(0, 50) || 'Untitled',
+      sourceType: row.data?.sourceType,
+      content: row.data?.content,
+      sourceMeta: row.data?.sourceMeta,
+      createdAt: row.created_at,
+      updatedAt: row.updated_at,
+    }));
+
+    return NextResponse.json({ success: true, items, count: items.length });
+  } catch (error) {
+    console.error('[API /knowledge/items] Error:', error);
+    return NextResponse.json({ success: true, items: [], count: 0 });
   }
 }
-