chore(deps): upgrade to React 19, react-dom 19, lucide-react v1, helmet v8 (v0.11.11 Beta)

- React + @types/react bumped to v19 (merged Dependabot PRs #22, #23, #25)
- react-dom + @types/react-dom aligned to v19 (PR #26 had conflicts; applied manually)
- lucide-react upgraded from 0.309 → 1.16 to satisfy React 19 peer deps (no API changes for our icon usage pattern)
- helmet upgraded 7 → 8; contentSecurityPolicy: false option unchanged
- jest + @types/jest bumped (dev-only, no runtime impact)
- TypeScript clean, Vite build passes, zero new errors

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

backend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mikrotik-manager-backend",
-  "version": "0.11.10-beta",
+  "version": "0.11.11-beta",
   "description": "Mikrotik Network Management Platform - Backend API",
   "main": "dist/index.js",
   "scripts": {