feat: Improve UI styling in ExpenseDetailsModal and ExpenseList, enhance authentication middleware caching, and optimize PDF generation for receipt fetching

components/ExpenseDetailsModal.vue

@@ -28,7 +28,7 @@
             {{ expense.DisplayPrice || expense.Price }}
           </div>
           <div v-if="expense.ConversionRate && expense.ConversionRate !== 1" class="conversion-info">
-            <span class="text-caption text-grey-darken-1">
+            <span class="text-caption text-grey-darken-3">
               Rate: {{ expense.ConversionRate }} | USD: {{ expense.DisplayPriceUSD }}
             </span>
           </div>

components/ExpenseList.vue

@@ -64,12 +64,12 @@
               
               <!-- Multiple receipts indicator -->
               <v-chip
-                v-if="expense.Receipt.length > 1"
                 size="x-small"
-                color="primary"
-                class="receipt-count-chip"
+                variant="flat"
+                :color="getCategoryColor(expense.Category)"
+                class="text-caption text-grey-darken-3"
               >
-                +{{ expense.Receipt.length - 1 }}
+                {{ expense.Category || 'Other' }}
               </v-chip>
             </div>