Management API upgrade returns 201 but creates no observable upgrade status

# Bug report - [x] I confirm this appears to be a Supabase platform / Management API bug, not an application bug. - [x] I searched the documentation and existing GitHub issues before filing. ## Describe the bug A hosted project's Postgres upgrade was accepted by the Management API, but the returned tracking ID never became observable and no global upgrade status was created. The upgrade eligibility response was clean: - `eligible: true` - selected `postgres_version: "17"` - selected `release_channel: "ga"` - selected `app_version: "supabase-postgres-17.6.1.147"` - no validation errors, warnings, unsupported extensions, read replicas, or logical replication slots - estimated duration: 1 hour The request: ```http POST /v1/projects/{ref}/upgrade Content-Type: application/json { "target_version": "17", "release_channel": "ga" } ``` returned HTTP 201 with a non-empty `tracking_id`. For more than the full estimated window, both status forms returned HTTP 200 with no status object: ```json { "databaseUpgradeStatus": null } ``` This occurred for: - `GET /v1/projects/{ref}/upgrade/status?tracking_id={tracking_id}` - `GET /v1/projects/{ref}/upgrade/status` After the estimate elapsed: - the project remained `ACTIVE_HEALTHY` - all project services were healthy - the database remained on `17.6.1.038` - upgrade eligibility continued to offer the same target - migration history, schema, and application data were unchanged No second upgrade request was submitted because the API provides no evidence that the accepted orchestration job was cancelled, rejected, queued, or safe to retry. ## To reproduce 1. Use a hosted project on an older Postgres 17 platform patch. 2. Confirm `GET /upgrade/eligibility` returns `eligible: true` with no blockers. 3. Submit the exact `postgres_version` and `release_channel` returned by eligibility to `POST /upgrade`. 4. Observe HTTP 201 and a non-empty tracking ID. 5. Poll `GET /upgrade/status` with that tracking ID and without it. 6. Observe `data…