Introduce a services module containing ApplicationService which wraps a
SecurityEventServiceImpl parameterized over Postgres repo type aliases.
Add a seawatch module that implements SecurityEventService for
ApplicationService by delegating fetch_events to the inner service.
Export both modules from application mod.

Add ClientServiceImpl providing client, redirect-uri and role management
with policy checks, webhook notifications and security event recording.
Add application-level client adapter (app/client) that delegates
ClientService to ApplicationService and wire required repositories and
types into the services setup.

Change create_service to build and return ApplicationService. Wrap
repositories and shared FerriskeyPolicy in Arc and pass cloned Arcs into
service implementations. Add new(...) constructors for many domain
services to accept Arc dependencies. Update
RandBytesRecoveryCodeRepository to take an Arc<HasherRepository> Add Arc
constructors and application builder

Remove the monolithic Service generic and its wide impl blocks across
domains. Introduce concrete *Impl structs (CoreServiceImpl,
AuthServiceImpl, ClientServiceImpl, etc.), move GenerateTokenInput into
authentication value_objects, simplify imports/type parameters, and
delete now-unused modules (authenticate.rs, grant_type_service.rs) and
the FerrisKeyService alias.