fix: fix non-interactive mode support to shell tool & terminate logic

[JackYPCOnline]

Description

fix the bug that non-interactive mode run infinitely in integration test

• Dual-Mode Operation: Added comprehensive support for both interactive and non-interactive execution through a new non_interactive_mode parameter
• Process Group Management: Improved command execution with better process isolation using os.setsid() for cleaner termination
• Terminal State Safety: Enhanced terminal settings handling to prevent issues in headless environments
• Signal Handling: Improved process termination with proper process group signaling
• Simplified API: Streamlined command normalization for more consistent behavior
• Update unit tests

Related Issues

[Link to related issues using #issue-number format]

Documentation PR

[Link to related associated PR in the agent-docs repo]

Type of Change

• [ x] Bug fix
• New Tool
• Breaking change
• Other (please describe):

Testing

[How have you tested the change?]
Yes. Unit tests and start strands agent.

• hatch fmt --linter
• hatch fmt --formatter
• hatch test --all

Checklist

• [ x] I have read the CONTRIBUTING document

• [ x] I have added tests that prove my fix is effective or my feature works

• [ x] I have updated the documentation accordingly

• [ x] I have added an appropriate example to the documentation to outline the feature

• [ x] My changes generate no new warnings

• [ x] Any dependent changes have been merged and published

• By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[JackYPCOnline]

also tested with integration test with different interactive mode and termination.

[zastrowm]

Have some questions, but don't see major blockers