fix(ios): derive TestFlight build number from App Store Connect

The beta lane took the build number from pubspec (FLUTTER_BUILD_NUMBER).
Re-running CI on the same commit re-submitted an already-taken build
number and failed with 409 ENTITY_ERROR.ATTRIBUTE.INVALID.DUPLICATE
(run 2045: build 157 was already on TestFlight).

Now the lane queries the latest TestFlight build for the current
marketing version (falling back to the pubspec value when nothing was
uploaded yet) and uploads latest + 1, so retries can never collide.

ios/fastlane/Fastfile

@@ -43,37 +43,60 @@ platform :ios do
     end
     
     UI.message "Using auth_key_path: #{auth_key_path}"
-    
+
+    # Authenticate to App Store Connect early:
+    # needed here by latest_testflight_build_number, not only by upload_to_testflight.
+    app_store_connect_api_key(
+      key_id: "325JS9JCZH",
+      issuer_id: "dfa27d1d-2bb8-4d4d-847e-0b32f9b880b3",
+      key_filepath: auth_key_path,
+      duration: 1200,
+      in_house: false
+    )
+
     # Configure Flutter for release mode
     UI.message "Configuring Flutter for release mode..."
     sh("cd .. && flutter build ios --config-only --release")
     
-    # Read build number from Flutter Generated.xcconfig
+    # Read version and build number from Flutter Generated.xcconfig.
+    # They are only a floor: the actual build number is derived from TestFlight below,
+    # so repeated CI runs on the same commit can never hit
+    # ENTITY_ERROR.ATTRIBUTE.INVALID.DUPLICATE ("bundle version must be higher").
     generated_xcconfig_path = File.join("..", "Flutter", "Generated.xcconfig")
+    flutter_build_name = nil
     flutter_build_number = nil
-    
+
     if File.exist?(generated_xcconfig_path)
       File.foreach(generated_xcconfig_path) do |line|
-        matches = line.match(/FLUTTER_BUILD_NUMBER=(.*)/)
-        if matches
-          flutter_build_number = matches[1].strip
-          break
+        if (m = line.match(/FLUTTER_BUILD_NAME=(.*)/))
+          flutter_build_name = m[1].strip
+        elsif (m = line.match(/FLUTTER_BUILD_NUMBER=(.*)/))
+          flutter_build_number = m[1].strip
         end
       end
     end
-    
-    if flutter_build_number.nil?
-      UI.user_error!("Could not find FLUTTER_BUILD_NUMBER in #{generated_xcconfig_path}")
+
+    if flutter_build_name.nil? || flutter_build_number.nil?
+      UI.user_error!("Could not find FLUTTER_BUILD_NAME/FLUTTER_BUILD_NUMBER in #{generated_xcconfig_path}")
     end
-    
-    UI.message "Flutter build number: #{flutter_build_number}"
-    
+
+    UI.message "Flutter version from pubspec: #{flutter_build_name} (#{flutter_build_number})"
+
+    asc_latest_build_number = latest_testflight_build_number(
+      app_identifier: "com.eatvioapp.app",
+      version: flutter_build_name,
+      initial_build_number: flutter_build_number.to_i
+    )
+
+    new_build_number = [flutter_build_number.to_i, asc_latest_build_number].max + 1
+    UI.message "Latest TestFlight build number: #{asc_latest_build_number} -> uploading build #{new_build_number}"
+
     match(type: "appstore", readonly: true)
-    
+
     # Set build number explicitly instead of incrementing
     increment_build_number(
       xcodeproj: "Runner.xcodeproj",
-      build_number: flutter_build_number
+      build_number: new_build_number
     )
 
     update_code_signing_settings(
@@ -93,22 +116,13 @@ platform :ios do
       export_team_id: "VL68C36HYS"
     )
 
-    app_store_connect_api_key(
-      key_id: "325JS9JCZH", 
-      issuer_id: "dfa27d1d-2bb8-4d4d-847e-0b32f9b880b3", 
-      key_filepath: auth_key_path,
-      duration: 1200,
-      in_house: false
-    )
-  
-    
     begin
       upload_to_testflight(
         skip_waiting_for_build_processing: true,
         skip_submission: true,
         distribute_external: false,
         notify_external_testers: false,
-        changelog: "TestFlight build #{flutter_build_number}",
+        changelog: "TestFlight build #{new_build_number}",
         verbose: true
       )
     rescue => ex