Register a new runtime image version.
Called by CI/CD after building and pushing a runtime image to the container registry. Creates or updates the version record in SurrealDB.
Requires Clerk authentication (session token or API key).
Args: body: Runtime version registration payload. service: RuntimeVersionService for persistence. user: Authenticated user from Clerk.
Returns: The persisted RuntimeVersion record.
Successful Response
A tracked runtime image version.
Identity fields (frozen): version: Semver string (e.g., "0.39.0"), used as SurrealDB record ID.
Metadata: image_url: Full container image URL for this runtime version. released_at: Timestamp when this version was released. changelog: Optional release notes in markdown.