feat(sprint-6): Phase 7 — Launch checklist, pricing page, legal templates

- docs/sprint-6/launch-checklist.md: comprehensive pre/post-launch checklist
- /pricing: public pricing page (Starter €19, Pro €49, Enterprise)
- /impressum, /datenschutz, /agb: legal page templates (placeholder text)
- (marketing) route group: public layout without auth
- Footer links to legal pages on login + portal
- i18n for marketing namespace (de + en)
- Fix pre-existing lint errors (unused vars, missing @stomp/stompjs types)

cannamanage-frontend/package.json

@@ -73,6 +73,7 @@
     "@eslint/compat": "1.2.7",
     "@ianvs/prettier-plugin-sort-imports": "4.4.1",
     "@playwright/test": "^1.60.0",
+    "@stomp/stompjs": "^7.3.0",
     "@tailwindcss/postcss": "4.0.17",
     "@tailwindcss/typography": "0.5.15",
     "@testing-library/jest-dom": "^6.9.1",
@@ -81,6 +82,7 @@
     "@types/node": "20",
     "@types/react": "19.0.12",
     "@types/react-dom": "19.0.4",
+    "@types/sockjs-client": "^1.5.4",
     "@vitejs/plugin-react": "^6.0.2",
     "eslint": "9.18.0",
     "eslint-config-next": "15.5.18",
@@ -92,6 +94,7 @@
     "postcss": "8",
     "prettier": "3.5.3",
     "prettier-plugin-tailwindcss": "0.6.11",
+    "sockjs-client": "^1.6.1",
     "tailwindcss": "4.1.3",
     "tw-animate-css": "1.2.5",
     "typescript": "5",