Write comprehensive test suite

[TonsOfFun]

Description

Create full test coverage for ActivePrompt engine using Rails testing best practices.

Test Types to Write

• Unit tests for models
• Controller tests
• System tests with Capybara
• Integration tests
• Performance tests

Model Tests

• AgentConfiguration validations and associations
• ToolConfiguration ordering and management
• AgentRelationship circular dependency prevention
• AlertRule condition checking
• JSON serialization

Controller Tests

• CRUD operations
• Turbo Stream responses
• Authentication/authorization
• Error handling
• Instrumentation events

System Tests

• Agent creation workflow
• Lexxy editor interactions
• Tool drag-and-drop
• Chart rendering
• Real-time updates

Test Fixtures

• Sample agents
• Tool configurations
• Mock SolidAgent data
• Performance metrics

Acceptance Criteria

• 90%+ test coverage
• All tests pass
• CI/CD pipeline green
• Performance benchmarks met