step 6 redesign: dashboard, sidebar sections, add menu, editor UX

Per 10-point UX spec:
- Contrast boosted (text #e4e4ef instead of #ccc)
- Dashboard view: badges, quick-actions, grouped sub-items/notes/files
- Notes tab filters by type=note, Files tab shows only files
- Tab placeholders: Actions, Worklog, Activity
- Single + Add button with dropdown menu (case/note/file/action/worklog)
- Sidebar navigation: Today, Inbox, Clients, Projects, Recipes, Docs, Archive
- Russian type labels (no raw CASE/note)
- Note editor: breadcrumb, title, readable-width textarea (720px)
- Wails-ready SPA: inline JS, fetch to /api/*, no external deps

docs/PLAN.md

@@ -14,9 +14,9 @@
 | 1 | Git init + Skeleton | ✅ выполнен |
 | 2 | Init + SQLite + First Migration | ✅ выполнен |
 | 3 | Nodes Repository + CRUD + CLI Node | ✅ выполнен |
-| 4 | Vault Files: Trash + File Service + CLI File | ⬜ не начат |
-| 5 | Markdown Notes: Create/Read/Save + CLI Note | ⬜ не начат |
-| 6 | Wails GUI MVP: Sidebar + Main Panel | ⬜ не начат |
+| 4 | Vault Files: Trash + File Service + CLI File | ✅ выполнен |
+| 5 | Markdown Notes: Create/Read/Save + CLI Note | ✅ выполнен |
+| 6 | Wails GUI MVP: Sidebar + Main Panel | ✅ выполнен |
 | 7 | Actions: Run URL/File/Command + GUI Tab | ⬜ не начат |
 | 8 | Worklog: Entries + Report + GUI Tab | ⬜ не начат |
 | 9 | FTS5 Search: Rebuild Index + GUI Search Bar | ⬜ не начат |