Add comprehensive tests for realm quoting behavior

Tests cover: - Default realm quoting - Custom realm with spaces - Special characters (quotes, backslashes) - Empty realm fallback to default - Unicode realm support Addresses review feedback about testing strconv.Quote behavior in WWW-Authenticate header per RFC 7617 compliance. 🤖 Generated with [Claude Code](https://claude.ai/code) Co-Authored-By: Claude <noreply@anthropic.com>

Author: 2 people

middleware/basic_auth_test.go

@@ -117,3 +117,64 @@ func TestBasicAuth(t *testing.T) {
 })
 }
 }
+
+func TestBasicAuthRealm(t *testing.T) {
+e := echo.New()
+mockValidator := func(u, p string, c echo.Context) (bool, error) {
+return false, nil // Always fail to trigger WWW-Authenticate header
+}
+
+tests := []struct {
+name string
+realm string
+expectedAuth string
+}{
+{
+name: "Default realm",
+realm: "Restricted",
+expectedAuth: `basic realm="Restricted"`,
+},
+{
+name: "Custom realm",
+realm: "My API",
+expectedAuth: `basic realm="My API"`,
+},
+{
+name: "Realm with special characters",
+realm: `Realm with "quotes" and \backslashes`,
+expectedAuth: `basic realm="Realm with \"quotes\" and \\backslashes"`,
+},
+{
+name: "Empty realm (falls back to default)",
+realm: "",
+expectedAuth: `basic realm="Restricted"`,
+},
+{
+name: "Realm with unicode",
+realm: "测试领域",
+expectedAuth: `basic realm="测试领域"`,
+},
+}
+
+for _, tt := range tests {
+t.Run(tt.name, func(t *testing.T) {
+req := httptest.NewRequest(http.MethodGet, "/", nil)
+res := httptest.NewRecorder()
+c := e.NewContext(req, res)
+
+h := BasicAuthWithConfig(BasicAuthConfig{
+Validator: mockValidator,
+Realm: tt.realm,
+})(func(c echo.Context) error {
+return c.String(http.StatusOK, "test")
+})
+
+err := h(c)
+
+var he *echo.HTTPError
+errors.As(err, &he)
+assert.Equal(t, http.StatusUnauthorized, he.Code)
+assert.Equal(t, tt.expectedAuth, res.Header().Get(echo.HeaderWWWAuthenticate))
+})
+}
+}