Cache lifecycle documentation

These pages describe contracts for how caches interact with domain behavior. Implementation lives under apps/worker/src/lib/services/cache/ and related services.

Document	Scope
user.md	Resolving relatedUsers for open tasks; invalidation when user profile changes
maintenance.md	Maintenance list/detail invalidation; purge; alignment with finalSnapshot
system.md	System settings / feature flags cache and validation consistency
session.md	Session vs domain cache; authorization prerequisites

Parent index: ../README.md.