fix: repair recognition — migrate vision model and fix XFile handling

- Replace decommissioned llama-3.2-11b-vision-preview with
  meta-llama/llama-4-scout-17b-16e-instruct (Groq deprecation)
- Use XFile.readAsBytes() instead of File(path).readAsBytes() so
  Android content URIs (from gallery picks) are read correctly
- Add maxWidth/maxHeight constraints to image picker calls to reduce
  payload size
- Increase receiveTimeout from 30s to 120s to accommodate slow vision AI
- Log recognition errors via debugPrint instead of swallowing them

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

client/lib/core/api/api_client.dart

@@ -9,7 +9,7 @@ class ApiClient {
     _dio = Dio(BaseOptions(
       baseUrl: baseUrl,
       connectTimeout: const Duration(seconds: 10),
-      receiveTimeout: const Duration(seconds: 30),
+      receiveTimeout: const Duration(seconds: 120),
       headers: {'Content-Type': 'application/json'},
     ));