fix: schedule status labels, Open Day halls, unsaved data guards

Schedule:
- Status badges use admin config labels (not hardcoded text) everywhere
- DayCard: level badge moved next to status badge
- Single location: hide "Все студии" tab, auto-select the only hall
- Group view: hide per-card address when all share same location
- Filter tooltip z-index fixed (above dropdowns)
- Trainer bio: status labels from config, not raw keys

Open Day:
- Hall name + address shown in schedule grid headers
- Only one class card editable at a time (edit/create mutually exclusive)
- Bigger action buttons (cancel/delete) on class cards
- Create as empty draft (not pre-filled with published status)
- Fix discount threshold input (allow delete to empty)
- Skip auto-save during partial date input

Admin:
- SectionEditor: unsaved data guard (force-save before navigation)
- Open Day + Team: same navigation guards
- Contact: removed working hours field
- TimeRangeField: allow end time hour changes
- Schedule cards: visible borders, 90min default duration
- Trainer bio: RichTextarea for description
- Open Day: RichTextarea for description

src/app/admin/contact/page.tsx

@@ -230,12 +230,6 @@ export default function ContactEditorPage() {
             />
           </div>
 
-          <InputField
-            label="Часы работы"
-            value={data.workingHours}
-            onChange={(v) => update({ ...data, workingHours: v })}
-          />
-
           <CollapsibleSection title="Адреса">
             <AddressList
               items={data.addresses ?? []}