Add TLS requirement fields to HTTP, database, and cache contracts

[RonaldHensbergen]

Scope

Extend contract definitions so consuming modules can declare and validate TLS requirements in a consistent, provider-neutral way.

Deliverables

• Update relevant contract kinds used for HTTP/database/cache interactions with TLS requirement fields.
• Keep backward compatibility rules explicit (required vs optional fields).

Acceptance criteria

• Contract definitions can express tls: required (or equivalent explicit requirement semantics).
• Existing valid profiles remain valid unless they explicitly opt into stricter TLS requirements.
• Validation paths for missing/invalid TLS requirement values are clearly defined.