Add expense tracking system with receipt management and currency conversion

- Add expense list and detail views with filtering capabilities
- Implement receipt image viewer and PDF export functionality
- Add currency conversion support with automatic rate updates
- Create API endpoints for expense CRUD operations
- Integrate with NocoDB for expense data persistence
- Add expense menu item to dashboard navigation

utils/types.ts

@@ -221,3 +221,63 @@ export interface Interest {
 export interface InterestsResponse {
   list: Interest[];
 }
+
+// Expense tracking types
+export interface ExpenseReceipt {
+  id: string;
+  url: string;
+  signedUrl: string;
+  title: string;
+  mimetype: string;
+  size: number;
+  width: number;
+  height: number;
+  thumbnails: {
+    tiny: { signedUrl: string };
+    small: { signedUrl: string };
+    card_cover: { signedUrl: string };
+  };
+}
+
+export type ExpenseCategory = "Food/Drinks" | "Shop" | "Online" | "Other";
+export type PaymentMethod = "Cash" | "Card";
+
+export interface Expense {
+  Id: number;
+  "Establishment Name": string;
+  Price: string; // Format: "45.99" (numeric value only)
+  currency: string; // ISO currency code: "EUR", "USD", "GBP", etc.
+  "Payment Method": PaymentMethod;
+  Category: ExpenseCategory;
+  Payer: string;
+  Time: string; // Format: "YYYY-MM-DD HH:mm:ss"
+  Contents: string; // Long text description
+  Receipt: ExpenseReceipt[];
+  Paid: boolean;
+  CreatedAt: string;
+  UpdatedAt: string;
+  
+  // Computed properties (added by API)
+  PriceNumber?: number; // Parsed price as number for calculations
+  CurrencySymbol?: string; // Display symbol: "€", "$", "£"
+  PriceUSD?: number; // Converted USD amount
+  ConversionRate?: number; // Exchange rate used (from currency to USD)
+  ConversionDate?: string; // When rate was fetched
+  DisplayPrice?: string; // "€45.99 ($48.12)" or just "€45.99" if USD
+  DisplayPriceUSD?: string; // "$48.12" formatted USD amount
+  FormattedDate?: string; // Formatted date string
+  FormattedTime?: string; // Formatted time string
+  FormattedDateTime?: string; // Formatted date-time string
+}
+
+export interface ExpenseFilters {
+  startDate?: string;
+  endDate?: string;
+  payer?: string;
+  category?: ExpenseCategory;
+}
+
+export interface ExpensesResponse {
+  list: Expense[];
+  PageInfo: PageInfo;
+}