refactor(realtime): the gateway asks a journey-access port instead of importing the journey domain

The websocket gateway injected JourneyDomainService to decide who may join
a journey's book room, so the realtime domain, which nearly every domain
imports for its broadcasts, depended on journey and closed a cycle through
all of them. It now injects a JOURNEY_ACCESS port declared in realtime;
JourneyAccessModule (global, imported by AppModule beside the gateway
module) binds it to the same JourneyDomainService method.

server/scripts/import-boundaries-baseline.json

@@ -2,69 +2,44 @@
   "fileCycles": [],
   "domainCycles": [
     "accommodations -> assignments",
-    "accommodations -> mcp-shared",
     "accommodations -> places",
-    "accommodations -> realtime",
     "addons -> memories",
     "addons -> transit",
     "assignments -> days",
     "assignments -> journey",
-    "assignments -> mcp-shared",
-    "assignments -> realtime",
     "atlas -> addons",
     "auth -> plugins",
     "budget -> addons",
-    "budget -> mcp-shared",
-    "budget -> realtime",
     "days -> accommodations",
     "days -> assignments",
-    "days -> mcp-shared",
     "days -> places",
-    "days -> realtime",
-    "files -> mcp-shared",
-    "files -> realtime",
     "geo -> maps",
     "integrations -> addons",
     "integrations -> assignments",
     "integrations -> atlas",
     "integrations -> journey",
-    "integrations -> mcp-shared",
     "integrations -> places",
-    "integrations -> realtime",
     "integrations -> reservations",
     "journey -> addons",
     "journey -> atlas",
-    "journey -> files",
     "journey -> memories",
     "journey -> photos",
-    "journey -> realtime",
     "maps -> geo",
-    "mcp-shared -> realtime",
     "memories -> addons",
-    "memories -> notifications",
     "memories -> photos",
-    "memories -> realtime",
-    "notifications -> realtime",
     "photos -> memories",
     "places -> accommodations",
     "places -> assignments",
     "places -> atlas",
     "places -> journey",
-    "places -> mcp-shared",
-    "places -> realtime",
     "plugins -> trips",
     "plugins -> vacay",
-    "realtime -> journey",
     "reservations -> accommodations",
     "reservations -> assignments",
     "reservations -> budget",
     "reservations -> days",
     "reservations -> integrations",
-    "reservations -> mcp-shared",
-    "reservations -> notifications",
-    "reservations -> realtime",
     "transit -> days",
-    "transit -> mcp-shared",
     "transit -> reservations",
     "trip-members -> auth",
     "trip-members -> trips",

server/src/nest/app.module.ts

@@ -64,6 +64,7 @@ import { SpaFallbackFilter } from './platform/spa-fallback.filter';
 import { PluginsModule } from './plugins/plugins.module';
 import { PublicApiModule } from './public-api/public-api.module';
 import { RealtimeGatewayModule } from './realtime/realtime-gateway.module';
+import { JourneyAccessModule } from './journey/journey-access.module';
 import { RealtimeModule } from './realtime/realtime.module';
 import { ReceiptScanModule } from './receipt-scan/receipt-scan.module';
 import { ReservationImportModule } from './reservation-import/reservation-import.module';
@@ -100,6 +101,7 @@ import { APP_FILTER, APP_GUARD, APP_INTERCEPTOR, APP_PIPE } from '@nestjs/core';
     DemoModule,
     RealtimeModule,
     RealtimeGatewayModule,
+    JourneyAccessModule,
     SchedulingModule,
     McpModule.forRoot({
       accessPolicy: trekMcpAccessPolicy,

server/src/nest/journey/journey-access.module.ts

@@ -0,0 +1,17 @@
+import { Global, Module } from '@nestjs/common';
+import { JOURNEY_ACCESS } from '../realtime/journey-access.types';
+import { JourneyDomainModule } from './journey-domain.module';
+import { JourneyDomainService } from './journey-domain.service';
+
+/**
+ * Binds the realtime gateway's JOURNEY_ACCESS port to JourneyDomainService.
+ * Global so RealtimeGatewayModule resolves it without importing the journey
+ * domain; AppModule imports it next to the gateway module.
+ */
+@Global()
+@Module({
+  imports: [JourneyDomainModule],
+  providers: [{ provide: JOURNEY_ACCESS, useExisting: JourneyDomainService }],
+  exports: [JOURNEY_ACCESS],
+})
+export class JourneyAccessModule {}

server/src/nest/realtime/journey-access.types.ts

@@ -0,0 +1,15 @@
+/**
+ * What the gateway asks before it lets a socket into a journey's book room.
+ *
+ * A port rather than JourneyDomainService itself: realtime is imported by
+ * nearly every domain for the broadcast facade, so depending on journey from
+ * here put realtime, journey and everything between them on one import cycle.
+ * The journey domain binds the token (JourneyAccessModule), and the answer is
+ * still the one the REST routes get.
+ */
+export const JOURNEY_ACCESS = Symbol('JOURNEY_ACCESS');
+
+export interface JourneyAccess {
+  /** Truthy when the user may open the journey. */
+  canAccessJourney(journeyId: number, userId: number): Promise<unknown>;
+}

server/src/nest/realtime/realtime-gateway.module.ts

@@ -2,7 +2,6 @@ import { Module, type OnModuleDestroy } from '@nestjs/common';
 import { MikroOrmModule } from '@mikro-orm/nestjs';
 import { RealtimeGateway } from './realtime.gateway';
 import { EphemeralTokenModule } from '../auth-core/ephemeral-token.module';
-import { JourneyDomainModule } from '../journey/journey-domain.module';
 import { AppSettings } from '../../db/entities/AppSettings.entity';
 import { Users } from '../../db/entities/Users.entity';
 import { Trips } from '../../db/entities/Trips.entity';
@@ -23,13 +22,13 @@ import { processRooms, RoomRegistry, roomsSlot } from './ws-state';
  * TrekWsAdapter already registered.
  */
 @Module({
-  // JourneyDomainModule for the book rooms: who may open a journey is asked
-  // of the same service the REST routes ask. Users/AppSettings: Plan 4 Task
+  // The book rooms ask JOURNEY_ACCESS, bound globally by JourneyAccessModule
+  // to the same service the REST routes ask. Users/AppSettings: Plan 4 Task
   // 1 — the handshake's password-version and require_mfa reads, moved off
   // DatabaseService onto UsersRepository/AppSettingsRepository. Trips: Plan 4
   // Task 2 — handleJoin's own canAccessTrip delegate, now TripsRepository
   // directly.
-  imports: [EphemeralTokenModule, JourneyDomainModule, MikroOrmModule.forFeature([Users, AppSettings, Trips])],
+  imports: [EphemeralTokenModule, MikroOrmModule.forFeature([Users, AppSettings, Trips])],
   // The room registry is the process-wide in-memory one; the constructor
   // below hands whichever one the container resolved to the broadcast
   // functions, so the gateway and the broadcasts never use two registries.

server/src/nest/realtime/realtime.gateway.ts

@@ -1,4 +1,4 @@
-import { Injectable, OnModuleDestroy } from '@nestjs/common';
+import { Inject, Injectable, OnModuleDestroy } from '@nestjs/common';
 import {
   ConnectedSocket,
   MessageBody,
@@ -30,7 +30,7 @@ import {
   userOf,
   type TrekWebSocket,
 } from './ws-state';
-import { JourneyDomainService } from '../journey/journey-domain.service';
+import { JOURNEY_ACCESS, type JourneyAccess } from './journey-access.types';
 import { readAppSetting } from '../common/app-settings.registry';
 import { runningVersion } from '../../app-config';
 
@@ -71,9 +71,10 @@ export class RealtimeGateway
     /*
      * For the book rooms, and injected rather than reimplemented: who may open
      * a journey is one question with one answer, and a second copy of it here
-     * is a second thing to keep in step with the REST routes.
+     * is a second thing to keep in step with the REST routes. Behind a port
+     * (journey-access.types.ts) so realtime does not import the journey domain.
      */
-    private readonly journeys: JourneyDomainService,
+    @Inject(JOURNEY_ACCESS) private readonly journeys: JourneyAccess,
     @InjectRepository(Users) private readonly users: UsersRepository,
     @InjectRepository(AppSettings) private readonly appSettings: AppSettingsRepository,
     // Room membership, behind its port. The container's provider, which