fix: improve jjad and jjac AI features with robust execution and error handling

[HotThoughts]

Description

Brief description of the changes in this PR.

Fixes #(issue)

Type of Change

• 🐛 Bug fix (non-breaking change which fixes an issue)
• ✨ New feature (non-breaking change which adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 Documentation update
• 🔧 Configuration change
• 🧹 Code cleanup/refactoring
• 🚀 Performance improvement

Changes Made

Testing

• I have tested this change locally
• I have added/updated tests as needed
• All existing tests pass
• I have tested the change with multiple Fish versions (if applicable)

Fish Environment

• Fish version:
• jj version:
• Operating System:

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have updated the CHANGELOG.md file
• Any dependent changes have been merged and published

Additional Notes

Any additional information, screenshots, or context about the PR.