Add isChildOfEpic() function that checks if an issue is a child of the configured epic by verifying the issue has the epic in its dependents with dependency_type="blocks". When EpicID is configured in witness config, only issues that block that epic will be considered for auto-spawning. Issues that cannot be verified are safely skipped. Closes gt-zhm5. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>