itdove/devaiflow#383: Enhance daf link to support session rename and in-agent usage

[itdove]

Now I have enough context to fill in the template.

Jira Issue: #383

Description

Enhances the daf link command to support session renaming via a new --rename-prefix option and enables it to be called from inside Claude sessions.

Motivation: As part of the effort to remove thin daf git command wrappers and leverage gh/glab CLI tools directly via skills (#383-#386), daf link needs to absorb the session-rename functionality currently embedded in daf git create. This is a prerequisite for removing daf git create (#384).

Changes:

• Added --rename-prefix option to daf link that renames the session to {prefix}-{issue_key_slug} (e.g., creation-itdove-devaiflow-456)
• Removed/conditionalized @require_outside_claude decorator so daf link can be called from inside Claude sessions
• Reuses existing issue_key_to_session_name() from sync_command.py for consistent slug generation
• Updated CLI option registration in main.py
• Added tests for the new rename functionality

Assisted-by: Claude

Testing

Steps to test

1. Pull down the PR
2. Create a test session: daf new my-test-session
3. Create a GitHub issue: gh issue create --title "Test issue" --body "test" --label enhancement
4. Link and rename: daf link my-test-session --jira "#<issue_number>" --rename-prefix creation
5. Verify the session was renamed to creation-<owner>-<repo>-<issue_number>
6. Verify issue_key and issue_metadata are set on the renamed session
7. Test calling daf link from inside a Claude session to confirm the @require_outside_claude restriction is lifted
8. Run the test suite: pytest tests/test_link_command.py

Scenarios tested

• daf link with --rename-prefix renames session correctly using issue_key_to_session_name() slug format
• daf link without --rename-prefix continues to work as before (no rename, just links metadata)
• daf link callable from inside Claude sessions (in-agent usage)
• Unit tests pass for the new rename functionality

Deployment considerations

• This code change is ready for deployment on its own
• This code change requires the following considerations before being deployed: