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

entrypoint.sh

@@ -38,6 +38,19 @@ pool.query(\`
   );
   CREATE INDEX IF NOT EXISTS idx_fs_sessions_user_id ON fs_sessions (user_id);
   CREATE INDEX IF NOT EXISTS idx_fs_sessions_project_id ON fs_sessions ((data->>'projectId'));
+  CREATE TABLE IF NOT EXISTS fs_knowledge_items (
+    id TEXT PRIMARY KEY DEFAULT gen_random_uuid()::text,
+    project_id TEXT NOT NULL,
+    data JSONB NOT NULL DEFAULT '{}'::jsonb,
+    created_at TIMESTAMP DEFAULT NOW(),
+    updated_at TIMESTAMP DEFAULT NOW()
+  );
+  CREATE INDEX IF NOT EXISTS idx_fs_knowledge_project_id ON fs_knowledge_items (project_id);
+  CREATE TABLE IF NOT EXISTS chat_conversations (
+    project_id TEXT PRIMARY KEY,
+    messages JSONB NOT NULL DEFAULT '[]',
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+  );
 \`).then(() => { console.log('App tables ready'); pool.end(); }).catch(e => { console.error('Table init error:', e.message); pool.end(); });
 "