[Providers] Normalize observation, ownership, and drift #41

Outcome

Make external state and corrective behavior deterministic across providers.

Scope

• Define normalized observations, managed/informational drift, ignored fields, ownership proofs, and deterministic corrective plans.

Acceptance criteria

• Unchanged observations produce no plan.
• Drift classifications are stable and ignored fields explicit.
• Adapters cannot mutate or delete resources without matching ownership evidence.

Test and evidence

• Observation, ownership, no-op, and drift golden tests.

Dependencies

• Blocked by #38.
• Blocked by #33.
• Blocked by #35.

References

• Architecture overview
• Security model