Tree captures not appearing in dev/test admin panel — S3 upload pipeline broken

**Describe the bug**
Tree captures uploaded via the Android app (v2.1.3, dev build) are not appearing in the dev or test admin panels. The app is confirmed to register uploads to S3 (wallet registration data is visible), but capture/tree data is not flowing through the backend pipeline. This blocks all current mobile testing efforts.

**To Reproduce**
Steps to reproduce the behavior:
1. Build and install the dev variant of the Android app (branch: release-2.1.3_candidate-1)
2. Register a new account and upload tree captures
3. Wait 5–10 minutes
4. Check [test-admin.treetracker.org/verify](https://test-admin.treetracker.org/verify) and the dev admin panel for the capture

**Expected behavior**
Uploaded tree captures appear in the admin panel within 1–5 minutes

**Actual behaviour**
No captures appear. Wallet registration data reaches S3 but captures/trees do not.

**Evidence**
- Test admin panel: last tree capture dated 30 Jul 2025
- Dev admin panel: last tree capture dated 12 Aug 2023
- S3 dev bucket shows wallet registration for email but captures and trees fields are null
- Multiple testers affected: email shows 50 test trees uploaded
- Dev admin inbox/messaging feature is also non-functional, blocking messaging tests
- App code is unchanged from the working production version, issue is backend-side

**Desktop (please complete the following information):**
App version | 2.1.3 (dev build)-- | --
Branch | release-2.1.3_candidate-1
S3 identity pool | eu-central-1:3f3395cc-3835-470d-8fd9-c96304a6b07f
Admin panels | test-admin.treetracker.org, dev admin

**Next steps**

- Investigate the S3-to-database pipeline for the dev and test environments
- Check why captures and trees are null while wallet_registrations succeed
- Investigate broken inbox/messaging feature in the dev admin panel
- Confirm whether a recent backend deployment broke the pipeline