refactor(trip-membership): domains ask TripAccessService who may see a trip

Thirty services, controllers, MCP tools and RPC handlers outside the trips
domain injected TripsRepository for one call, findAccessible. They now
inject TripAccessService from the trip-membership leaf, in the same
constructor slot under the same field name; it answers with the same
access row (or undefined) and binds the id exactly as given, so each
caller keeps its own coercion and its own 404, 403 or tool error.

server/tests/unit/plugins/addon-gates.rpc.test.ts

@@ -26,6 +26,7 @@ import type { AddonsService } from '../../../src/nest/addons/addons.service';
 import type { UsersRepository } from '../../../src/db/repositories/Users.repository';
 import type { RpcRequest, RpcError } from '../../../src/nest/plugins/protocol/envelope';
 import { makeDeps } from '../../helpers/rpc-host-deps';
+import { TripAccessService } from '../../../src/nest/trip-membership/trip-access.service';
 
 const req = (method: string, params: Record<string, unknown> = {}): RpcRequest => ({ k: 'req', id: 'x', method, params });
 
@@ -81,7 +82,7 @@ function build(addonOn: boolean) {
       // SV8 — Plan 3i: DemoService.isDemoUserId, the shared demo-gate primitive.
       { isDemoUserId: async () => false } as never),
     new CollectionsRpc(spyService(calls, 'collections'), guards),
-    new CostsRpc(spyService(calls, 'budget'), db, { broadcast: vi.fn() } as never, guards, spyService(calls, 'membership')),
+    new CostsRpc(spyService(calls, 'budget'), new TripAccessService(db), { broadcast: vi.fn() } as never, guards, spyService(calls, 'membership')),
   ]);
   const granted = new Set([
     'db:read:collab', 'db:write:collab', 'db:read:journal', 'db:write:journal',