Enhance user profile management and Gravatar integration

- Added email field to user profile API and frontend components for better user identification.
- Implemented PATCH /map/api/me endpoint to update user email, enhancing user experience.
- Introduced useGravatarUrl composable for generating Gravatar URLs based on user email.
- Updated profile and layout components to display user avatars using Gravatar, improving visual consistency.
- Enhanced development documentation to guide testing of navbar and profile features.

frontend-nuxt/composables/useMapApi.ts

@@ -99,6 +99,14 @@ export function useMapApi() {
     return request<MeResponse>('me')
   }
 
+  async function meUpdate(body: { email?: string }) {
+    await request('me', {
+      method: 'PATCH',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(body),
+    })
+  }
+
   /** Public: whether first-time setup (no users) is required. */
   async function setupRequired(): Promise<{ setupRequired: boolean }> {
     const res = await fetch(`${apiBase}/setup`, { credentials: 'include' })
@@ -225,6 +233,7 @@ export function useMapApi() {
     login,
     logout,
     me,
+    meUpdate,
     oauthLoginUrl,
     oauthProviders,
     setupRequired,