Fold the journey domain into Nest and finish the MCP migration

journeyService (1324 LOC, 36 exports) and journeyShareService (203) become
JourneyDomainService and JourneyShareService. Every SQL statement, error string
and broadcast is the one that shipped.

The two could never be split: the share service gates on isOwner, which lives in
the domain service, so it injects it.

JourneyDomainModule is a leaf carrying just the two services. Places,
assignments and the plugin host each need a handful of journey functions;
importing JourneyModule for that would drag MemoriesModule and both photo
providers into their graphs. Same shape as TrekPhotosModule.

The 23 tools in src/mcp/tools/journey.ts become JourneyMcp. src/mcp/tools/ is
down to _shared.ts and registerTools() no longer fans out to anything.

journey.bridge.ts keeps four exports, for the journey resources in
src/mcp/resources.ts that register at import time.

McpAccessMode is host-augmentable now. journey:share is neither read nor write,
so the three share tools would have had to be opaque predicates - and predicates
bypass the access policy entirely, invisible to the boot-time scope gate. A
scope typo in one would ship as a silently ungated tool. McpAccessModeRegistry
mirrors McpAccessGroupRegistry; unaugmented, mode stays 'read' | 'write'.

Fixes a latent bug in tests/helpers/mcp-test-controllers.ts: it constructed
PlacesService with five of eight arguments. tsconfig only includes src, so
nothing typechecked it, and the missing dependencies were harmless until the
journey skeleton hooks landed on the place write paths.

journey.mcp.ts arrived from src/mcp/ at 14.5% branch coverage - the legacy
registrar had no test file of its own. 40 tool tests take it to 93.4%, and 25
cases for the skeleton lifecycle, the photo gallery and the preference row take
the domain service from 73.9% to 82.8%.

server/src/nest/plugins/plugins.module.ts

@@ -1,4 +1,5 @@
 import { Module } from '@nestjs/common';
+import { JourneyDomainModule } from '../journey/journey-domain.module';
 import { PluginsController } from './plugins.controller';
 import { PluginsFeedController } from './plugins-feed.controller';
 import { PluginsProxyController } from './plugins-proxy.controller';
@@ -57,7 +58,7 @@ import { TripMembershipModule } from '../trip-membership/trip-membership.module'
 @Module({
   // The DI-native domain services the plugin host wiring injects
   // (PluginHostDepsFactory); DatabaseModule is @Global, so not listed.
-  imports: [TagsModule, CategoriesModule, BudgetModule, ReservationsModule, TodoModule, PackingModule, DaysModule, AssignmentsModule, LlmParseModule, FilesModule, CollabModule, VacayModule, TripsModule, PermissionsModule, AuditModule, AddonsModule, PlacesModule, CollectionsModule, AtlasModule, NotificationsModule, TripMembershipModule],
+  imports: [TagsModule, CategoriesModule, BudgetModule, ReservationsModule, TodoModule, PackingModule, DaysModule, AssignmentsModule, LlmParseModule, FilesModule, CollabModule, VacayModule, TripsModule, PermissionsModule, AuditModule, AddonsModule, PlacesModule, CollectionsModule, AtlasModule, NotificationsModule, TripMembershipModule, JourneyDomainModule],
   controllers: [PluginsController, PluginsFeedController, PluginsProxyController, PluginFrameController, PlaceDetailsController, TripWarningsController, ViewContributionsController, TripCardContributionsController, PluginPhotosController, PluginCalendarController, MapMarkersController, MapLayersController, PluginRoutesController, DayScheduleController, DayTintsController, PdfSectionsController, AtlasLayersController, JournalEntryRowsController, PluginUserSettingsController, PluginOAuthController, PluginActivityController],
   providers: [PluginsService, PluginRuntimeService, PluginRegistryService, PluginOAuthService, PluginHostDepsFactory],
   // Exported so the admin addon-toggle handler can cascade-disable plugins whose