Add complete framework for cross-simulator embodied AI actions:

Core Modules:
- ActionExecutor: lifecycle management, retry, timeout, cancellation
- ExecutionContext: complete execution state tracking
- UnifiedActionInterface: unified API gateway for all actions
- Config: environment-based configuration management

Domain Layer:
- NavigateAction: complete navigation domain model
- ObjectId, Vector3Value: value objects for entities and positions
- SemanticActionType, CompletionStatus: action enumerations

Adapter Framework:
- BaseSimulatorAdapter: abstract base class for all adapters
- AdapterFactory: factory pattern for adapter creation
- ISimulatorAdapter: simulator adapter interface
- MockNavigateAdapter: configurable mock for testing

Verification:
- NavigateVerifier: distance-based verification

Testing:
- 150+ test cases with 90.71% average coverage
- Unit + Integration tests
- CI/CD ready

Documentation:
- Complete technical docu...