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/package.json

@@ -169,23 +169,7 @@
     "rootDir": "src",
     "testRegex": ".*\\.spec\\.ts$",
     "testPathIgnorePatterns": [
-      "/node_modules/",
-      "<rootDir>/core/auth/auth.controller.spec.ts",
-      "<rootDir>/core/auth/services/auth.service.spec.ts",
-      "<rootDir>/core/auth/services/token.service.spec.ts",
-      "<rootDir>/core/comment/comment.service.spec.ts",
-      "<rootDir>/core/group/group.controller.spec.ts",
-      "<rootDir>/core/group/services/group.service.spec.ts",
-      "<rootDir>/core/page/page.controller.spec.ts",
-      "<rootDir>/core/page/services/page.service.spec.ts",
-      "<rootDir>/core/search/search.controller.spec.ts",
-      "<rootDir>/core/search/search.service.spec.ts",
-      "<rootDir>/core/space/services/space.service.spec.ts",
-      "<rootDir>/core/space/space.controller.spec.ts",
-      "<rootDir>/core/user/user.controller.spec.ts",
-      "<rootDir>/core/workspace/services/workspace.service.spec.ts",
-      "<rootDir>/integrations/environment/environment.service.spec.ts",
-      "<rootDir>/integrations/storage/storage.service.spec.ts"
+      "/node_modules/"
     ],
     "transform": {
       "happy-dom.+\\.js$": [
@@ -206,7 +190,7 @@
       "^.+\\.(t|j)sx?$": "ts-jest"
     },
     "transformIgnorePatterns": [
-      "/node_modules/(?!(\\.pnpm/)?(nanoid|uuid|image-dimensions|marked|happy-dom)(@|/))"
+      "/node_modules/(?!(\\.pnpm/)?(nanoid|uuid|image-dimensions|marked|happy-dom|lib0)(@|/))"
     ],
     "collectCoverageFrom": [
       "**/*.(t|j)s"