feat: refine admin forms, attendance and finance workflows

Squash merge PR #23.

Included changes:
- complete occupancy check-in required fields/default payload
- improve responsive admin management pages
- fix attendance edge cases and attendance period config
- refine wallet/finance-related workflow handling

Checks:
- npm run typecheck -w apps/admin
- npm run typecheck -w apps/server

apps/admin/src/pages/Occupancies/occupancy-form.ts

@@ -1,5 +1,34 @@
 import type { Dayjs } from 'dayjs';
 
+export interface CheckInFormValues {
+  studentId: number;
+  roomId: number;
+  checkInDate: Dayjs;
+  billingStartDate?: Dayjs;
+  stayType?: string;
+  collectDeposit?: boolean;
+  depositAmount?: number;
+  notes?: string;
+  bedId: number;
+  lockerId?: number;
+}
+
+export const buildCheckInPayload = (values: CheckInFormValues) => {
+  const collectDeposit = values.collectDeposit ?? false;
+  return {
+    studentId: values.studentId,
+    roomId: values.roomId,
+    checkInDate: values.checkInDate.format('YYYY-MM-DD'),
+    billingStartDate: (values.billingStartDate || values.checkInDate).format('YYYY-MM-DD'),
+    stayType: values.stayType || 'short',
+    collectDeposit,
+    depositAmount: collectDeposit ? values.depositAmount ?? 500 : undefined,
+    notes: values.notes?.trim() || undefined,
+    bedId: values.bedId,
+    lockerId: values.lockerId || undefined,
+  };
+};
+
 export interface TransferFormValues {
   newRoomId: number;
   newBedId: number;