v0.2.0

Added

• Impersonation / act-as: Current carries the real actor alongside the
  effective user; config.actor_method, config.sod_identity, and a
  read-only-while-impersonating MutationGuard.
• Append-only audit ledger (current_scope_events) with a read-only index.
• scope_for(Model) — the list-side complement to allowed_to?, from the same
  grants (STI-aware: normalizes to base_class).
• Scoped-role picker (Role → Subject → Type → Record) + CurrentScope::Scopeable,
  with an opt-in current_scope_searchable_scope hook for indexed search.
• Host test helpers grant_role! / grant_scoped_role! (survive the request cycle).
• CurrentScope::GatingTripwire — opt-in mixin that catches ungated controllers.
• CurrentScope.grant! + current_scope:grant rake task to bootstrap the first admin.
• Pagination for the subjects page and events index.

Changed

• Separation of duties is opt-in: config.sod_actions now defaults to [].
• Declared Rails floor is >= 8.1 (the management UI relies on params.expect
  array semantics introduced in 8.1); the CI test job exercises it.
• config.audit is tri-state: false | true | :strict.

Security

• Production guardrail: config.allow_mutations_while_impersonating = true raises
  at boot in production unless CURRENT_SCOPE_ALLOW_PROD_IMPERSONATION_MUTATIONS
  is set.
• The impersonation-boundary API raises when config.actor_method is unset,
  instead of silently running with inert act-as security.

Fixed

• with_current_user restores the ambient context correctly across the whole
  >= 8.1 floor (was version-fragile).