fix(export): update frontend to call new /admin/db/export endpoint

- Changed exportSnapshot to call GET /api/admin/db/export?type=inventory
- Changed exportAuditTrail to call GET /api/admin/db/export?type=audit
- Fixed token key: auth_token → inventory_token
- Changed HTTP method from POST to GET
- Fixes 404 errors when exporting from admin page

frontend/hooks/useExport.ts

@@ -49,10 +49,9 @@ export function useExport(): UseExportReturn {
     setError(null);
 
     try {
-      const token = localStorage.getItem('auth_token');
-      const response = await axios.post(
-        `/api/admin/exports/inventory-snapshot?format=${format}`,
-        {},
+      const token = localStorage.getItem('inventory_token');
+      const response = await axios.get(
+        `/api/admin/db/export?format=${format}&type=inventory`,
         {
           responseType: "blob",
           headers: { 'Authorization': `Bearer ${token}` }
@@ -85,10 +84,9 @@ export function useExport(): UseExportReturn {
     setError(null);
 
     try {
-      const token = localStorage.getItem('auth_token');
-      const response = await axios.post(
-        `/api/admin/exports/audit-trail?format=${format}`,
-        {},
+      const token = localStorage.getItem('inventory_token');
+      const response = await axios.get(
+        `/api/admin/db/export?format=${format}&type=audit`,
         {
           responseType: "blob",
           headers: { 'Authorization': `Bearer ${token}` }