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]/vision/route.ts

@@ -1,15 +1,19 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { getAdminDb } from '@/lib/firebase/admin';
+import { getServerSession } from 'next-auth';
+import { authOptions } from '@/lib/auth/authOptions';
+import { query } from '@/lib/db-postgres';
 
-/**
- * Save vision answers to Firestore
- */
 export async function POST(
   request: NextRequest,
   { params }: { params: Promise<{ projectId: string }> }
 ) {
   try {
     const { projectId } = await params;
+    const session = await getServerSession(authOptions);
+    if (!session?.user?.email) {
+      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+    }
+
     const body = await request.json();
     const { visionAnswers } = body;
 
@@ -20,29 +24,41 @@ export async function POST(
       );
     }
 
-    const adminDb = getAdminDb();
+    const rows = await query<{ id: string; data: any }>(
+      `SELECT p.id, p.data FROM fs_projects p
+       JOIN fs_users u ON u.id = p.user_id
+       WHERE p.id = $1 AND u.data->>'email' = $2 LIMIT 1`,
+      [projectId, session.user.email]
+    );
 
-    // Save vision answers and mark ready for MVP
-    await adminDb.collection('projects').doc(projectId).set(
-      {
-        visionAnswers: {
-          q1: visionAnswers.q1,
-          q2: visionAnswers.q2,
-          q3: visionAnswers.q3,
-          allAnswered: true,
-          updatedAt: visionAnswers.updatedAt || new Date().toISOString(),
-        },
-        readyForMVP: true,
-        currentPhase: 'mvp',
-        phaseStatus: 'ready',
+    if (rows.length === 0) {
+      return NextResponse.json({ error: 'Project not found' }, { status: 404 });
+    }
+
+    const current = rows[0].data ?? {};
+    const updated = {
+      ...current,
+      visionAnswers: {
+        q1: visionAnswers.q1,
+        q2: visionAnswers.q2,
+        q3: visionAnswers.q3,
+        allAnswered: true,
+        updatedAt: visionAnswers.updatedAt || new Date().toISOString(),
       },
-      { merge: true }
+      readyForMVP: true,
+      currentPhase: 'mvp',
+      phaseStatus: 'ready',
+      updatedAt: new Date().toISOString(),
+    };
+
+    await query(
+      `UPDATE fs_projects SET data = $1::jsonb WHERE id = $2`,
+      [JSON.stringify(updated), projectId]
     );
 
     console.log(`[Vision API] Saved vision answers for project ${projectId}`);
 
     // Trigger MVP generation (async - don't wait)
-    console.log(`[Vision API] Triggering MVP generation for project ${projectId}...`);
     fetch(new URL(`/api/projects/${projectId}/mvp-checklist`, request.url).toString(), {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
@@ -65,4 +81,3 @@ export async function POST(
     );
   }
 }
-