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.

internal/app/handlers/handlers_test.go

@@ -287,6 +287,51 @@ func TestAPIMePassword(t *testing.T) {
 	}
 }
 
+func TestAPIMeUpdate_UpdatesEmail(t *testing.T) {
+	env := newTestEnv(t)
+	env.createUser(t, "alice", "pass", app.Auths{app.AUTH_MAP})
+	sid := env.loginSession(t, "alice")
+
+	patchBody := `{"email":"test@example.com"}`
+	req := withSession(httptest.NewRequest(http.MethodPatch, "/map/api/me", strings.NewReader(patchBody)), sid)
+	req.Header.Set("Content-Type", "application/json")
+	rr := httptest.NewRecorder()
+	env.h.APIMeUpdate(rr, req)
+	if rr.Code != http.StatusOK {
+		t.Fatalf("expected 200, got %d: %s", rr.Code, rr.Body.String())
+	}
+
+	req2 := withSession(httptest.NewRequest(http.MethodGet, "/map/api/me", nil), sid)
+	rr2 := httptest.NewRecorder()
+	env.h.APIMe(rr2, req2)
+	if rr2.Code != http.StatusOK {
+		t.Fatalf("expected 200 on GET /me, got %d", rr2.Code)
+	}
+	var meResp struct {
+		Username string `json:"username"`
+		Email    string `json:"email"`
+	}
+	if err := json.NewDecoder(rr2.Body).Decode(&meResp); err != nil {
+		t.Fatal(err)
+	}
+	if meResp.Email != "test@example.com" {
+		t.Fatalf("expected email test@example.com, got %q", meResp.Email)
+	}
+}
+
+func TestAPIRouter_Me_MethodNotAllowed(t *testing.T) {
+	env := newTestEnv(t)
+	env.createUser(t, "alice", "pass", app.Auths{app.AUTH_MAP})
+	sid := env.loginSession(t, "alice")
+
+	req := withSession(httptest.NewRequest(http.MethodPost, "/map/api/me", nil), sid)
+	rr := httptest.NewRecorder()
+	env.h.APIRouter(rr, req)
+	if rr.Code != http.StatusMethodNotAllowed {
+		t.Fatalf("expected 405 for POST /me, got %d", rr.Code)
+	}
+}
+
 func TestAdminUsers_RequiresAdmin(t *testing.T) {
 	env := newTestEnv(t)
 	env.createUser(t, "alice", "pass", app.Auths{app.AUTH_MAP})