Remove duplicate except ImportError blocks in cloud_resources_steps.py
(B025 violations in step_sandbox_create, step_sandbox_commit,
step_sandbox_rollback). Apply ruff format to 5 files flagged by the
format check.
- Extract AWS-specific logic into cloud_aws.py and cloud_providers.py to keep all files under the 500-line limit (cloud.py: 490 lines, cloud_aws.py: 498 lines, cloud_providers.py: 181 lines)
- Fix sandbox test regression: change cloud_resources.feature sandbox create scenario from "aws" to "gcp" provider (AWS no longer raises NotImplementedError)
- Add ImportError handling to step_sandbox_create/commit/rollback in cloud_resources_steps.py
- Remove all 9 type: ignore comments from production code using proper type narrowing and boto3/botocore type stubs in typings/
- Move plan_id validation before logger.info() in all three sandbox methods (fail-fast principle)
- Fix exception suppression: discover_aws_resources() now propagates exceptions instead of catching bare Exception
- Move deferred imports (PhysVirt, ResourceCapabilities, _derive_child_id) to module level in cloud_aws.py
- Split cloud_aws_sdk_steps.py (755 lines) into focused modules: cloud_aws_helpers.py, cloud_aws_session_steps.py, cloud_aws_discover_steps.py, cloud_aws_sandbox_steps.py
- Add CHANGELOG.md entry for AWS SDK integration feature
- Update robot/helper_cloud_resources.py to handle ImportError/ NotImplementedError for AWS sandbox operations
ISSUES CLOSED: #1021
HAL9000