- Add 'Send to Workflow' menu item to checkpoint context menu (templates/checkpoints.html)
- Implement sendCheckpointToWorkflow() method in CheckpointContextMenu.js
- Use unified 'Model' terminology for toast messages instead of differentiating checkpoint/diffusion model
- Add translation keys: checkpoints.contextMenu.sendToWorkflow, uiHelpers.workflow.modelUpdated, modelFailed
- Complete translations for all 10 locales (en, zh-CN, zh-TW, ja, ko, de, fr, es, ru, he)