refactor(api): buses only in services, atomic commands, @Prop schemas

- Mongo read models are @Schema/@Prop classes (SchemaFactory), still
  loose: the props declared are the indexed or shaped ones.
- CommandBus and QueryBus are used by the application services alone.
  Duplicating a ticket, bulk updates, CSV imports, proposals and
  emptying the trash chain several commands, so they are service
  methods now and their composite commands are gone; every command
  handler is atomic. No forwardRef is needed.
- The due-date and trash timers are entry points: they live in the
  presenters and call the services. The automations event handler has
  its own file and calls AutomationsService.
- The tracker's user directory asks IdentityService; the composition
  root hands the identity application module to the tracker
  infrastructure (withIdentity), with no global module.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/api/tracker/application/src/index.ts

@@ -8,6 +8,8 @@ export * from './lib/releases.service';
 export * from './lib/changes.service';
 export * from './lib/workflows.service';
 export * from './lib/blockers.service';
+export * from './lib/bulk-change';
+export * from './lib/proposals';
 export * from './lib/proposal-quota.service';
 export * from './lib/notifications.service';
 export * from './lib/notifications';