[Providers] Define typed lifecycle and capability interfaces #38

Outcome

Give all providers one narrow discovery, plan, apply, observe, update, and delete contract.

Scope

• Define versioned capabilities, cancellation context, ownership, external identities, validation, and lifecycle interfaces.

Acceptance criteria

• Unsupported features fail during validation or planning.
• Provider-native payloads cannot leak through public resources.
• Interface versions and cancellation behavior are testable.

Test and evidence

• Accepted interface ADR and compile-time contract tests.

Dependencies

• Blocked by #19.
• Blocked by #33.

References

• Architecture overview