fix(realtime): CI gate fixes surfaced by Phase 11 smoke tests

- no-direct-socket-io: extend allowlist to cover apps/*/src/**/*.test.ts so
  the realtime-ping e2e integration test can import socket.io/socket.io-client
  directly; add two valid test cases to keep the rule's own test suite green
- tsconfig.json (root): add root-level tsconfig with experimentalDecorators +
  emitDecoratorMetadata and no "include" so tsx 4.21.0's createFilesMatcher
  resolves decorator config for all workspace packages, not just web-next's
  own source tree
- web-next dev script: pass TSX_TSCONFIG_PATH=../../tsconfig.json so the
  custom Node server uses the root tsconfig for all modules it loads
- next.config.mjs: add @repo/core-events and @repo/core-realtime to
  transpilePackages so Next.js webpack can resolve their workspace source files
- server.ts: replace static authContainer import with a dynamic import inside
  IRealtimeAuthenticator.authenticate so Inversify decorators are applied only
  after bindAll() has already populated the container

All CI gates pass: lint (0 errors), typecheck, 20 tests (incl. realtime-ping
e2e), boundaries (0 issues).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web-next/package.json

@@ -5,7 +5,7 @@
   "type": "module",
   "scripts": {
     "build": "echo 'Next.js build requires full environment — use pnpm dev or docker'",
-    "dev": "tsx server.ts",
+    "dev": "TSX_TSCONFIG_PATH=../../tsconfig.json tsx server.ts",
     "start": "node --import tsx server.ts",
     "lint": "eslint .",
     "test": "vitest run --passWithNoTests",