fix: export guard dependencies so cross-module @UseGuards resolves

NestJS resolves a guard referenced via @UseGuards(SomeGuard) using the
consuming module's injector, not the guard's own declaring module's
injector. OidcAuthGuard and TripMembershipGuard are shared across
several feature modules, so every constructor dependency they need
(UsersRepository/UsersService, TripMembersRepository, etc.) must be
re-exported by AuthModule/TripsLibModule/UsersLibModule, not just the
guard classes themselves. Found via the Phase 02 end-to-end smoke test
against a mocked IdP, which failed to boot the API before this fix.

backend/libs/trips/src/trips.module.ts

@@ -1,4 +1,4 @@
-import { Module } from '@nestjs/common';
+import { Global, Module } from '@nestjs/common';
 import { DatabaseModule } from '../../database/src';
 import { TripsRepository } from './trips.repository';
 import { TripsService } from './trips.service';
@@ -14,6 +14,7 @@ import { TravelersService } from './travelers.service';
 import { TripPreferenceOverridesRepository } from './trip-preference-overrides.repository';
 import { TripPreferenceOverridesService } from './trip-preference-overrides.service';
 
+@Global()
 @Module({
   imports: [DatabaseModule],
   providers: [
@@ -32,12 +33,18 @@ import { TripPreferenceOverridesService } from './trip-preference-overrides.serv
     TripPreferenceOverridesService,
   ],
   exports: [
+    TripsRepository,
     TripsService,
+    TripSettingsRepository,
     TripSettingsService,
+    TripMembersRepository,
     TripMembersService,
     TripMembershipGuard,
+    TripInvitationsRepository,
     TripInvitationsService,
+    TravelersRepository,
     TravelersService,
+    TripPreferenceOverridesRepository,
     TripPreferenceOverridesService,
   ],
 })