feat: add cash in/out UI and hide drawer balance from cashier

- Cash In / Cash Out buttons in drawer dialog when open
- Amount + reason form, adjustment history with IN/OUT badges
- Drawer badge shows "Drawer Open" without balance (manager info only)
- API helpers for addAdjustment and getAdjustments

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/admin/src/api/pos.ts

@@ -90,9 +90,20 @@ export interface Product {
 
 // --- Query Keys ---
 
+export interface DrawerAdjustment {
+  id: string
+  drawerSessionId: string
+  type: string
+  amount: string
+  reason: string
+  createdBy: string
+  createdAt: string
+}
+
 export const posKeys = {
   transaction: (id: string) => ['pos', 'transaction', id] as const,
   drawer: (locationId: string) => ['pos', 'drawer', locationId] as const,
+  drawerAdjustments: (id: string) => ['pos', 'drawer-adjustments', id] as const,
   products: (search: string) => ['pos', 'products', search] as const,
   discounts: ['pos', 'discounts'] as const,
 }
@@ -160,4 +171,10 @@ export const posMutations = {
 
   lookupUpc: (upc: string) =>
     api.get<Product>(`/v1/products/lookup/upc/${upc}`),
+
+  addAdjustment: (drawerId: string, data: { type: string; amount: number; reason: string }) =>
+    api.post<DrawerAdjustment>(`/v1/drawer/${drawerId}/adjustments`, data),
+
+  getAdjustments: (drawerId: string) =>
+    api.get<{ data: DrawerAdjustment[] }>(`/v1/drawer/${drawerId}/adjustments`),
 }