test-infra: re-enable 16 disabled server suites (jest DI + lib0 ESM) (#56)

16 suites were disabled via testPathIgnorePatterns due to two root causes: lib0
ESM not transformed (the @hocuspocus/server -> lib0/decoding.js chain) and stock
'should be defined' specs built via Test.createTestingModule without providers.
Add lib0 to transformIgnorePatterns; convert the 14 DI placeholders to direct
new X(...) instantiation with stub deps (keeping a real construct smoke test);
re-enable the suites. Also updates the public-share limiter test to assert the
fail-closed behavior from #62 (surfaced now that the suite runs). Full server
suite: 67 passed, 689 tests.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/server/src/integrations/environment/environment.service.spec.ts

@@ -1,15 +1,14 @@
-import { Test, TestingModule } from '@nestjs/testing';
 import { EnvironmentService } from './environment.service';
 
+// Direct instantiation with a stub ConfigService, mirroring the rest of these
+// unit specs.
 describe('EnvironmentService', () => {
   let service: EnvironmentService;
 
-  beforeEach(async () => {
-    const module: TestingModule = await Test.createTestingModule({
-      providers: [EnvironmentService],
-    }).compile();
-
-    service = module.get<EnvironmentService>(EnvironmentService);
+  beforeEach(() => {
+    service = new EnvironmentService(
+      {} as any, // configService
+    );
   });
 
   it('should be defined', () => {