debug(tax): Add console logging for tax rate creation

Added detailed console logging to debug why tax rates are not being saved:
- Log request data before sending
- Log API response
- Log success/error callbacks
- Invalidate both tax-settings and tax-suggested queries on success

This will help identify if:
1. API request is being sent correctly
2. API response is successful
3. Query invalidation is working
4. Frontend state is updating

Please test and check browser console for logs.

admin-spa/src/routes/Settings/Tax.tsx

@@ -54,14 +54,20 @@ export default function TaxSettings() {
   // Create tax rate
   const createMutation = useMutation({
     mutationFn: async (data: any) => {
-      return api.post('/settings/tax/rates', data);
+      console.log('[Tax] Creating rate:', data);
+      const response = await api.post('/settings/tax/rates', data);
+      console.log('[Tax] Create response:', response);
+      return response;
     },
-    onSuccess: () => {
+    onSuccess: (data) => {
+      console.log('[Tax] Create success:', data);
       queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
+      queryClient.invalidateQueries({ queryKey: ['tax-suggested'] });
       setShowAddRate(false);
       toast.success(__('Tax rate created'));
     },
     onError: (error: any) => {
+      console.error('[Tax] Create error:', error);
       toast.error(error?.message || __('Failed to create tax rate'));
     },
   });
@@ -99,7 +105,8 @@ export default function TaxSettings() {
   // Quick add suggested rate
   const quickAddMutation = useMutation({
     mutationFn: async (suggestedRate: any) => {
-      return api.post('/settings/tax/rates', {
+      console.log('[Tax] Quick adding rate:', suggestedRate);
+      const response = await api.post('/settings/tax/rates', {
         country: suggestedRate.code,
         state: '',
         rate: suggestedRate.rate,
@@ -109,12 +116,17 @@ export default function TaxSettings() {
         compound: 0,
         shipping: 1,
       });
+      console.log('[Tax] Quick add response:', response);
+      return response;
     },
-    onSuccess: () => {
+    onSuccess: (data) => {
+      console.log('[Tax] Quick add success:', data);
       queryClient.invalidateQueries({ queryKey: ['tax-settings'] });
+      queryClient.invalidateQueries({ queryKey: ['tax-suggested'] });
       toast.success(__('Tax rate added'));
     },
     onError: (error: any) => {
+      console.error('[Tax] Quick add error:', error);
       toast.error(error?.message || __('Failed to add tax rate'));
     },
   });