[Bug]: Schema-version Mismatch Forces a DB wipe, Silently Breaking all RestApi Routes (404) with no Self-Healing

Please select the area the issue is related to

Area/Management (Management API or Management Portal UI), Area/Operator (Kubernetes operator for AI Gateway or Regular Gateway)

Please select the aspect the issue is related to

Aspect/API (API backends, definitions, contracts, interfaces, OpenAPI)

Description

After a gateway-controller upgrade, the controller failed to start with

unsupported schema version N, expected 3; delete the database to recreate. 

The controller's only offered remedy is to delete the database. So we deleted the PVC (default SQLite backend, DB on a PVC).

After it restarted on a fresh DB, all RestApi-backed routes started returning 404. The RestApi resources were all still present and showing Programmed=True, so from kubectl everything looked healthy while the gateway served 404s. Restarting the controller didn't also help; the only fix was deleting and recreating each RestApi.

It is also worth noting the default SQLite backend (single-file, single-writer, single RWO PVC, single replica) is also a single point of data loss with no HA, while the Postgres backend is implemented but still documented as "future".

Steps to Reproduce

1. Deploy api-platform-operator and deploy APIGateway + few RestAPIs.
2. Check the behavior of RestAPIs after PVC clean up and controller restart

Severity Level of the Issue

Severity/Blocker (Core functionality is broken and consumer is blocked. Need immediate attention)

Environment Details (with versions)

Gateway operator version: 0.8.0
api-platform/helm-charts/gateway chart version: 1.1.0

Start in gateway/gateway-controller and reproduce the schema-version failure by cleaning the SQLite PVC and restarting the api-platform-operator with existing RestAPIs. Trace how the controller handles the mismatch and how RestAPI resources become programmed while serving 404s. Done should include a defined recovery path that avoids unnecessary data loss and verifies routes after controller restart; compare the documented PostgreSQL backend where relevant.