feat: redesign zametki page layout and date format

- Move "Add" button below textarea
- Move "Resolved" button below date (removed float-end)
- Show only HH:MM for note creation time via new formatTime helper

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

frontend/app.js

@@ -307,6 +307,11 @@ createApp({
       const d = new Date(dateStr);
       return d.toLocaleString('ru-RU');
     },
+    formatTime(dateStr) {
+      if (!dateStr) return '';
+      const d = new Date(dateStr);
+      return d.toLocaleTimeString('ru-RU', { hour: '2-digit', minute: '2-digit' });
+    },
     async loadEquipmentTypes() {
       try {
         this.equipmentTypes = await fetchJSON('/equipment-types/');