feat(docker-watcher): phase 14 - frontend polish & modern UI

Design system with CSS custom properties (light/dark themes).
38 Lucide SVG icon components. Dark mode with system preference.
EN/RU localization with i18n store. Skeleton loaders, empty states,
toggle switches, micro-interactions. Responsive sidebar with
mobile hamburger menu. All pages polished with consistent styling.

plans/docker-watcher-core/PLAN.md

@@ -36,7 +36,7 @@ A self-hosted tool that automates Docker container deployment with Nginx Proxy M
 - [x] Phase 11: Frontend Embed & Real-Time Updates [domain: fullstack] → [subplan](./phase-11-embed-sse.md)
 - [x] Phase 12: Hardening [domain: backend] → [subplan](./phase-12-hardening.md)
 - [x] Phase 13: Volumes & Environment [domain: fullstack] → [subplan](./phase-14-volumes-env.md)
-- [ ] Phase 14: Frontend Polish & Modern UI [domain: frontend] → [subplan](./phase-13-ui-polish.md)
+- [x] Phase 14: Frontend Polish & Modern UI [domain: frontend] → [subplan](./phase-13-ui-polish.md)
 
 ### Parallel Execution Notes
 
@@ -59,8 +59,8 @@ A self-hosted tool that automates Docker container deployment with Nginx Proxy M
 | Phase 10: Settings & Deploy | frontend | ✅ Complete | ⬜ Pending | ⏭️ Skip (Big Bang) | ✅ |
 | Phase 11: Embed & SSE | fullstack | ✅ Complete | ⬜ Pending | ⏭️ Skip (Big Bang) | ✅ |
 | Phase 12: Hardening | backend | ✅ Complete | ⬜ Pending | ⏭️ Skip (Big Bang) | ✅ |
-| Phase 13: Volumes & Env | fullstack | ✅ Complete | ⬜ Pending | ⏭️ Skip (Big Bang) | ⬜ |
-| Phase 14: UI Polish | frontend | ⬜ Not Started | ⬜ | ✅ Required (Final) | ⬜ |
+| Phase 13: Volumes & Env | fullstack | ✅ Complete | ⬜ Pending | ⏭️ Skip (Big Bang) | ✅ |
+| Phase 14: UI Polish | frontend | ✅ Complete | ⬜ Pending | ✅ Required (Final) | ⬜ |
 
 ## Amendment Log