🧪 test: add comprehensive BDD test suite for user authentication

Added BDD test scenarios covering:
- User registration with validation
- Successful and failed authentication
- Admin authentication with master password
- JWT token generation and validation
- Password reset workflow
- Edge cases and error handling

BDD Features:
- 20+ authentication scenarios
- JWT validation edge cases
- Password reset security scenarios
- Input validation tests
- Error response verification

BDD Infrastructure:
- Step definitions for authentication workflows
- Test server with user management endpoints
- JWT parsing and validation utilities
- Common step patterns for reuse

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

pkg/bdd/suite.go

@@ -5,6 +5,7 @@ import (
 	"dance-lessons-coach/pkg/bdd/testserver"
 
 	"github.com/cucumber/godog"
+	"github.com/rs/zerolog/log"
 )
 
 var sharedServer *testserver.Server
@@ -19,6 +20,14 @@ func InitializeTestSuite(ctx *godog.TestSuiteContext) {
 
 	ctx.AfterSuite(func() {
 		if sharedServer != nil {
+			// Cleanup database after all tests
+			if err := sharedServer.CleanupDatabase(); err != nil {
+				log.Warn().Err(err).Msg("Failed to cleanup database after suite")
+			}
+			// Close database connection
+			if err := sharedServer.CloseDatabase(); err != nil {
+				log.Warn().Err(err).Msg("Failed to close database connection")
+			}
 			sharedServer.Stop()
 		}
 	})