Add CI/CD pipeline, feedback modal, Atlas qualys_id fallback, and health endpoint

- Rewrite .gitlab-ci.yml with proper stages, blocking tests, staging
  environment on dev box, and SSH-based production deploy to 71.85.90.6
- Add POST /api/health endpoint for pipeline verification
- Add POST /atlas/hosts/:hostId/refresh-cache for Atlas cache staleness
- AtlasSlideOutPanel: auto-resolve qualys_id from Atlas vulnerabilities,
  prefer qualys_id over active_host_findings_id, retry on failure
- Add FeedbackModal component with bug report button in header and
  feature request in UserMenu, creates GitLab issues via /api/feedback
- Fix all frontend test failures (ESM transforms, TextDecoder polyfill,
  fast-check resolution, App.test.js boilerplate replacement)
- Fix root package.json test script to run jest
- Add deploy/ directory with staging systemd service and setup script

frontend/package.json

@@ -44,7 +44,7 @@
   },
   "jest": {
     "transformIgnorePatterns": [
-      "node_modules/(?!(fast-check)/)"
+      "node_modules/(?!(fast-check|pure-rand|react-markdown|rehype-sanitize|mermaid|d3|d3-.*|internmap|delaunator|robust-predicate|devlop|hast-util-.*|mdast-util-.*|micromark.*|unist-.*|unified|bail|trough|vfile.*|property-information|comma-separated-tokens|space-separated-tokens|decode-named-character-reference|character-entities|ccount|escape-string-regexp|markdown-table|trim-lines|zwitch|longest-streak|html-void-elements|stringify-entities|character-entities-html4|character-entities-legacy|character-reference-invalid)/)"
     ],
     "moduleNameMapper": {
       "^pure-rand/(.*)$": "<rootDir>/node_modules/pure-rand/lib/$1.js"