- Policy struct: matcher Proc, max_age, warn_at, enforce_action, notify_channels, triggers
- Builder validates all required fields at .build, raises BuilderError with the policy name
- DSL exposes top-level 'policy' method via 'with builder yield' so all
builder methods (description, match, max_age, enforce, notify_via, etc.)
are receiver-less inside the block
- Symbol literals autocast to Action/Channel/Trigger enums on direct calls;
Symbol overload for splat parameters (notify_via :telegram, :email)
- Evaluator subscribes to bus, fires PolicyViolation + RotationScheduled
(rotate_immediately) or AlertRaised (notify_only/quarantine) when overdue
- 15 unit specs cover Policy.matches?/overdue?/in_warning_window?,
Builder validation, DSL syntax with closures, evaluator action dispatch