Refactor: Fully migrated to direct PostgreSQL, implemented Public API v1, fixed Vercel deployment conflicts, and updated documentation

app/api/merchants/auth/route.ts

@@ -1,5 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
-import { supabaseAdmin } from '@/lib/supabase-admin';
+import { db } from '@/lib/db';
 import { cookies } from 'next/headers';
 
 export async function POST(req: NextRequest) {
@@ -12,20 +12,15 @@ export async function POST(req: NextRequest) {
 
         // 1. Resolve merchant by ID or short_id
         const isUUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i.test(identifier);
+        
+        const queryText = isUUID 
+            ? 'SELECT * FROM merchants WHERE id = $1 LIMIT 1'
+            : 'SELECT * FROM merchants WHERE short_id = $1 LIMIT 1';
+        
+        const result = await db.query(queryText, [identifier]);
+        const merchant = result.rows[0];
 
-        const query = supabaseAdmin
-            .from('merchants')
-            .select('*');
-
-        if (isUUID) {
-            query.eq('id', identifier);
-        } else {
-            query.eq('short_id', identifier);
-        }
-
-        const { data: merchant, error } = await query.single();
-
-        if (error || !merchant) {
+        if (!merchant) {
             return NextResponse.json({ error: 'Firma bulunamadı.' }, { status: 404 });
         }