fix: booking duration calculation, tip page auth, and UI polish across frontend

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/testutils/jwt/jwt.go

@@ -45,7 +45,7 @@ func GenerateTestToken(userID, role string) string {
 }
 
 func GenerateAdminToken() string {
-	return GenerateTestToken("admin-test-001", "admin")
+	return GenerateTestToken("admintest001", "admin")
 }
 
 func GenerateVerifiedUserToken(userID string) string {