controller-change-review

# Controller Change Review Skill ## When to use Use this skill when changes affect: - `internal/controller/` - `internal/apply/` - `internal/reconcile/` - `internal/transform/` - `internal/config/` - `internal/httpserver/` - `cmd/controller/` - `deploy/` --- ## Core invariants (MUST NOT BREAK) Always preserve: - Reconciliation must be **idempotent** - Controller must be **safe under retries** - Backoff must be **bounded and non-aggressive** - Leader election must not be bypassed - Garbage collection must never delete unrelated resources - Apply must remain **safe and scoped** - Traefik CRDs must remain **compatible** --- ## Review checklist ### Reconciliation loop - Does the loop remain safe under repeated execution? - Are external calls (Pangolin API) guarded against failures? - Is change detection (ETag/hash) preserved? ### Apply logic - Are resources applied using server-side apply safely? - Are field managers consistent? - Are partial updates avoided? ### Garbage collection - Only deletes resources owned by this controller? - Label selectors correct? - No risk of deleting shared/global resources? ### Transformation - Traefik objects correctly generated? - Routing, middleware, services preserved? - No invalid CRDs produced? ### Config handling - Defaults preserved? - Env + file merging still correct? - No breaking changes to config fields? ### HTTP server / observability - Health and readiness endpoints still valid? - Metrics preserved? --- ## Required validation Run: ```bash task test task test:integration go vet ./... ``` Optional deep validation: ```bash task ci ``` --- ## Expected output - Summary of change impact - Risks identified - Required fixes (if any) - Validation commands executed