feat: auto-convert feature requests to discussions

Add GitHub Action to automatically move feature request issues to
Discussions, keeping Issues tab focused on bug reports.

Changes:
- Update feature request template to add 'feature-request' label
- Create workflow to auto-convert labeled issues to discussions
- Support manual conversion via workflow_dispatch
- Auto-close and lock converted issues with discussion link

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/feature_request.md

@@ -2,7 +2,7 @@
 name: Feature request
 about: Suggest an idea for this project
 title: ''
-labels: ''
+labels: 'feature-request'
 assignees: ''
 
 ---