Story 9.5 — Implement hidden --override escape hatch to bypass catalog validation

**Epic:** #506 — Infrastructure Version Management

Provide an advanced, undocumented escape hatch for expert users who need to apply version combinations outside the catalog.

**Acceptance criteria:**
- Hidden flag (e.g. `--override`) skips catalog validation and applies declared `host` and `cluster` versions verbatim
- Flag is NOT documented in user-facing help (`--help` output)
- When the flag is used, emit a prominent warning K8s event and a warning log entry before proceeding
- Flag is intentionally unsupported; no guarantees on correctness of arbitrary version combinations