Deploy to App Store fails instantly: "Codemagic build error: RangeError (length): Invalid value: Valid value range is empty: 0" (API returns HTTP 500)

Project: ernex-fitness-309ykn (Vitagrit40), branch main, first-ever store deployment for this project.

Every "Deploy to App Store" attempt fails within a few seconds showing the toast: "Codemagic build error: RangeError (length): Invalid value: Valid value range is empty: 0". Deployment History stays empty ("No deployments yet"), and no signing certificates are ever created on the Apple Developer account, so the failure happens before the Codemagic build actually starts.

Network inspection shows POST https://api.flutterflow.io/v2/submitCodemagicBuild returning HTTP 500. Additionally, "generated_code" snapshot exports for this project have been consistently returning server 500s (normal project pushes and typed SDK refreshes work fine). This looks like a server-side codegen/export failure specific to our project.

We are on a launch deadline (store submission planned Aug 10). Could the FlutterFlow team check server logs for project ernex-fitness-309ykn? Recent failed attempts: Aug 7-8, ~21:30-22:45 UTC.

1) Fixed Firebase App Check providers (was Debug): iOS = App Attest with DeviceCheck fallback, Android = Play Integrity. (This cleared an earlier, different pre-deploy error.)

2) Created a new App Store Connect API key with Admin role (originally App Manager), re-uploaded the .p8 and updated Key ID in Mobile Deployment.

3) Verified bundle ID com.ernex.vitagrit40 matches in FlutterFlow, App Store Connect (App ID 6793646518) and Apple Developer portal Identifiers; launcher/adaptive icons are set; set App Version 1.0.0 and Build Number (also tried leaving build number empty).

4) Deleted a corrupted unnamed custom theme color and a duplicate (#14201a) that previously caused "Two or more colors exist with same base name ''" push errors.

5) Confirmed no GitHub repo is connected (deployment source = FlutterFlow), project issues checker is green, and status.flutterflow.io shows no incident.

None of this changed the error. Network tab shows POST /v2/submitCodemagicBuild -> HTTP 500 on every attempt, and generated_code exports also return 500 for this project.