Split PluginsModule into four, and gate coverage per domain

PluginsModule was 21 controllers, 24 domain imports and 10 providers in one
class, which made it the hub most of the Nest graph ran through: AdminModule
imported it for a single cascade-disable call and inherited all of it. It is now
PluginsRuntimeModule (supervisor, capability router, hook contracts),
PluginContributionsModule (the 14 read-only hook controllers, moved to
contributions/), PluginOAuthModule (the credential leaf, moved to oauth/) and a
composition root that keeps the install and delivery controllers. AdminModule
imports the runtime alone.

The three plugin files that reached for the db singleton alongside the injected
DatabaseService no longer do. plugin-host-state and signature-status take the
connection from the caller, and the three per-user settings functions that were
bare exports 'so the RPC host wiring can call them directly' are now
PluginUserSettingsService - the host wiring is providers, so it injects them.

Coverage moves from one repo-wide 80% to a per-domain ratchet. The single number
let a well-covered domain subsidise a thin one: booking-import sits at 50% and
integrations at 20%, and the aggregate still cleared the bar, so either could
have lost another ten points unnoticed. Each domain now carries its own measured
floor, regenerated by scripts/coverage-thresholds.mjs.

Two test-side findings on the way:

expect(undefined).toContain(SomeClass) PASSES in this vitest version - it only
throws for a string needle. Every '<X> is listed in its module providers' guard
was written that way, so all twelve of them silently stopped guarding the moment
their class moved. They go through expectRegisteredProvider now, which asserts
the array shape first.

The atlas region test paid for the one-off decompression of the multi-MB admin1
bundle inside its own 5s budget, which is why it failed under load and passed
alone. The bundle is warmed in beforeAll instead.

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

@@ -0,0 +1,87 @@
+import { Module } from '@nestjs/common';
+import { DiscoveryModule } from '@nestjs/core';
+import { PluginsService } from './plugins.service';
+import { PluginUserSettingsService } from './plugin-user-settings.service';
+import { PluginRuntimeService } from './plugin-runtime.service';
+import { PluginHooks } from './plugin-hooks.service';
+import { PluginRegistryService } from './registry/registry.service';
+import { PluginRpcHostFactory } from './host/plugin-rpc-host.factory';
+import { PluginRpcRegistryService } from './host/rpc-kit/registry.service';
+import { PluginGuardsModule } from './host/plugin-guards.module';
+import { PluginOAuthModule } from './oauth/plugin-oauth.module';
+import { DbRpc } from './host/rpc/db.rpc';
+import { MetaRpc } from './host/rpc/meta.rpc';
+import { HostSurfaceRpc } from './host/rpc/host-surface.rpc';
+import { WeatherModule } from '../weather/weather.module';
+import { TagsModule } from '../tags/tags.module';
+import { CategoriesModule } from '../categories/categories.module';
+import { BudgetModule } from '../budget/budget.module';
+import { ReservationsModule } from '../reservations/reservations.module';
+import { TodoModule } from '../todo/todo.module';
+import { PackingModule } from '../packing/packing.module';
+import { DaysModule } from '../days/days.module';
+import { AssignmentsModule } from '../assignments/assignments.module';
+import { LlmParseModule } from '../llm-parse/llm-parse.module';
+import { FilesModule } from '../files/files.module';
+import { CollabModule } from '../collab/collab.module';
+import { VacayModule } from '../vacay/vacay.module';
+import { TripsModule } from '../trips/trips.module';
+import { PlacesModule } from '../places/places.module';
+import { PermissionsModule } from '../permissions/permissions.module';
+import { AuditModule } from '../audit/audit.module';
+import { AddonsModule } from '../addons/addons.module';
+import { CollectionsModule } from '../collections/collections.module';
+import { AtlasModule } from '../atlas/atlas.module';
+import { NotificationsModule } from '../notifications/notifications.module';
+import { TripMembershipModule } from '../trip-membership/trip-membership.module';
+import { JourneyDomainModule } from '../journey/journey-domain.module';
+
+/**
+ * The plugin execution half (#plugins, M1/M2): the process supervisor, the
+ * capability router that every child talks to, and the hook contracts the host calls
+ * back through.
+ *
+ * The domain import list has to be COMPLETE, not just "whatever this module's own
+ * code needs". Every `@PluginController()` provider in the container contributes part
+ * of the 113-method wire surface, and PluginRpcRegistryService validates total
+ * coverage at boot — so a domain reachable only from AppModule would make this module
+ * fail to start in any test app that assembles a subset. WeatherModule is in the list
+ * for exactly that reason and for nothing else.
+ *
+ * Split out of PluginsModule so a consumer that needs the runtime alone — AdminModule
+ * cascade-disabling plugins whose addon was just turned off — does not also pull in
+ * 20 HTTP controllers it never calls.
+ */
+@Module({
+  imports: [
+    // What lets PluginRpcRegistryService find the @PluginController providers at boot.
+    DiscoveryModule,
+    // A leaf that hands the resource gates to the domain modules. It must not be this
+    // module: the domains would then have to import this one back and close a cycle.
+    PluginGuardsModule,
+    PluginOAuthModule,
+    WeatherModule, TagsModule, CategoriesModule, BudgetModule, ReservationsModule,
+    TodoModule, PackingModule, DaysModule, AssignmentsModule, LlmParseModule,
+    FilesModule, CollabModule, VacayModule, TripsModule, PlacesModule,
+    PermissionsModule, AuditModule, AddonsModule, CollectionsModule, AtlasModule,
+    NotificationsModule, TripMembershipModule, JourneyDomainModule,
+  ],
+  providers: [
+    PluginsService,
+    PluginUserSettingsService,
+    PluginRuntimeService,
+    PluginRegistryService,
+    PluginRpcHostFactory,
+    PluginRpcRegistryService,
+    // Owns no wire method; declares and performs all 18 host-to-plugin hook calls.
+    PluginHooks,
+    // The wire surface that belongs to no domain: the plugin's own sqlite, its
+    // namespaced entity metadata, and the host-mediated calls (user lookup,
+    // broadcasts, notifications, LLM, OAuth, scheduler).
+    DbRpc,
+    MetaRpc,
+    HostSurfaceRpc,
+  ],
+  exports: [PluginRuntimeService, PluginRegistryService, PluginsService, PluginUserSettingsService, PluginHooks],
+})
+export class PluginsRuntimeModule {}