Summary

This PR adds template export functionality to the Coder UI, addressing issue #17859. Users can now export templates directly from the web interface without requiring CLI access.

Changes

Frontend API

• Added downloadTemplateVersion function to site/src/api/api.ts
• Supports both TAR (default) and ZIP formats
• Uses existing /api/v2/files/{fileId} endpoint with format parameter

UI Enhancement

• Added "Export as TAR" and "Export as ZIP" options to template dropdown menu
• Positioned logically between "Duplicate" and "Delete" actions
• Uses download icon from Lucide React for consistency

User Experience

• Files automatically named as {templateName}-{templateVersion}.{extension}
• Immediate download trigger on click
• Proper error handling with console logging
• Clean blob URL management to prevent memory leaks

Testing

The implementation has been tested for:

• ✅ TypeScript compilation
• ✅ Proper function signatures and types
• ✅ UI component integration
• ✅ Error handling structure

Screenshots

The export options appear in the template dropdown menu:

• Export as TAR (default format, compatible with coder template pull)
• Export as ZIP (compressed format for easier handling)

Fixes

Closes #17859

Notes

This enhancement makes template management more accessible for users who:

• Don't have CLI access
• Manage deployments on devices without Coder CLI
• Prefer web-based workflows
• Need to transfer templates between environments

The implementation follows existing patterns in the codebase and maintains consistency with the current UI design.