Add enums, AuthService, and integrate backend registration endpoints

- Add separate enum files: BuildingType, PropertyStatus, BookingStatus, CommissionType, IdentityType, UserRole, City, LoginMethod, OwnerType, CustomerType
- Add AuthService (addToken/getToken/deleteToken)
- Update api.js: use AuthService, add Owner/Add and Customer/Add endpoints
- Update login page to use AuthService for token storage
- Rewrite owner register: 3-step flow with OwnerType dropdown, backend integration, OTP verification
- Rewrite tenant register: 2-step flow with CustomerType dropdown, backend integration, OTP verification
- Update homepage and property detail to use enums instead of hardcoded maps
- Update AddPropertyForm to import from enums directly
- Add console logs and status toasts linked to API response messages

app/services/AuthService.js

@@ -0,0 +1,51 @@
+/**
+ * AuthService
+ * Manages authentication tokens securely using localStorage.
+ * 
+ * Methods:
+ *   addToken(token)   — store JWT token
+ *   getToken()        — retrieve JWT token
+ *   deleteToken()     — remove JWT token
+ *
+ * Usage:
+ *   import AuthService from '@/app/services/AuthService';
+ *   AuthService.addToken(token);
+ *   const token = AuthService.getToken();
+ *   AuthService.deleteToken();
+ */
+const TOKEN_KEY = 'auth_token';
+
+const AuthService = Object.freeze({
+  /**
+   * Store token in localStorage
+   * @param {string} token — JWT string
+   */
+  addToken(token) {
+    if (!token || typeof token !== 'string') {
+      console.error('[AuthService] addToken: invalid token', token);
+      return;
+    }
+    localStorage.setItem(TOKEN_KEY, token);
+    console.log('[AuthService] Token stored');
+  },
+
+  /**
+   * Retrieve token from localStorage
+   * @returns {string|null}
+   */
+  getToken() {
+    const token = localStorage.getItem(TOKEN_KEY);
+    console.log('[AuthService] getToken:', token ? '***exists***' : null);
+    return token;
+  },
+
+  /**
+   * Remove token from localStorage
+   */
+  deleteToken() {
+    localStorage.removeItem(TOKEN_KEY);
+    console.log('[AuthService] Token deleted');
+  },
+});
+
+export default AuthService;