🧪 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/steps/README.md

@@ -0,0 +1,50 @@
+# BDD Steps Organization
+
+This folder contains the step definitions for the BDD tests, organized by domain for better maintainability and scalability.
+
+## Structure
+
+```
+pkg/bdd/steps/
+├── greet_steps.go        # Greet-related steps (v1 and v2 API)
+├── health_steps.go       # Health check and server status steps
+├── auth_steps.go         # Authentication and user management steps
+├── common_steps.go       # Shared steps used across multiple domains
+├── steps.go             # Main registration file that ties everything together
+└── README.md            # This file
+```
+
+## Design Principles
+
+1. **Domain Separation**: Steps are grouped by functional domain
+2. **Single Responsibility**: Each file focuses on a specific area of functionality
+3. **Reusability**: Common steps are shared via `common_steps.go`
+4. **Scalability**: Easy to add new domains as the application grows
+
+## Adding New Steps
+
+1. **For new domains**: Create a new `*_steps.go` file following the existing pattern
+2. **For existing domains**: Add to the appropriate domain file
+3. **For shared functionality**: Add to `common_steps.go`
+4. **Register all steps**: Update `steps.go` to include the new steps
+
+## Step Naming Convention
+
+- Use descriptive, action-oriented names
+- Follow the pattern: `i[Action][Object]` or `the[Object][State]`
+- Example: `iRequestAGreetingFor`, `theAuthenticationShouldBeSuccessful`
+
+## Testing the Steps
+
+Run BDD tests with:
+```bash
+go test ./features/... -v
+```
+
+## Future Domains
+
+As the application grows, consider adding:
+- `payment_steps.go` - Payment processing steps
+- `notification_steps.go` - Notification and email steps
+- `admin_steps.go` - Admin-specific functionality steps
+- `api_steps.go` - General API interaction patterns