fix: add Prefer:return=representation to Supabase REST calls for INSERT/PATCH

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

api/game.php

@@ -70,7 +70,8 @@ switch ($action) {
             'starting_fen' => 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
             'current_fen' => 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
             'move_count' => 0,
-            'moves' => '[]',
+            'moves' => json_encode([]),
+            'game_state' => json_encode([]),
             'started_at' => date('c'),
         ];
 

config/database.php

@@ -27,6 +27,10 @@ function supabase_rest(string $method, string $endpoint, array $data = [], ?stri
         $data = [];
     }
 
+    if ($method === 'POST' || $method === 'PATCH') {
+        $headers[] = 'Prefer: return=representation';
+    }
+
     $ch = curl_init($url);
     curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
     curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);