feat: schedule filters overhaul, local fonts, configurable statuses/levels

Schedule filters:
- Airbnb-style filter modal with sections: directions, trainer, status, level, days, time
- Multi-select trainer filter with search input
- Custom time range (from-to) with preset shortcuts
- Gold tag design for class types, statuses, and levels
- Hover tooltips on level/status options with descriptions from config
- Filter icon button inline with view toggle (По дням / По группам)

Admin schedule:
- Configurable experience levels and statuses (add/edit/reorder/delete)
- New scheduleConfig DB section with auto-save
- Status/level dropdowns in class editor read from config
- Status select built dynamically from config
- New status field on ScheduleClass for custom statuses

Other:
- Local fonts (Inter + Oswald) bundled in public/fonts — no Google Fonts dependency
- SelectField combobox: search in main input field, no separate search inside dropdown
- Fix carousel trainer label flash on drag release

src/lib/db.ts

@@ -520,6 +520,7 @@ const SECTION_KEYS = [
   "news",
   "contact",
   "popups",
+  "scheduleConfig",
 ] as const;
 
 export function getSiteContent(): SiteContent | null {
@@ -557,6 +558,16 @@ export function getSiteContent(): SiteContent | null {
       instagramHint: "По вопросам пишите в Instagram",
     },
     contact: sections.contact,
+    scheduleConfig: sections.scheduleConfig ?? {
+      levels: [
+        { value: "Начинающий/Без опыта", description: "Для тех, кто только начинает" },
+        { value: "Продвинутый", description: "Для учеников с опытом от 6 месяцев" },
+      ],
+      statuses: [
+        { key: "hasSlots", label: "Есть места", description: "В группе есть свободные места" },
+        { key: "recruiting", label: "Набор открыт", description: "Идёт набор в новую группу" },
+      ],
+    },
     team: {
       title: teamSection.title || "",
       members: members.map(({ id, ...rest }) => rest),