#7392 fix(workflow): preserve canvas and deploy modal behavior

Summary

• preserve the temporary connection edge while dragging the new-block picker
• keep deploy output selection interactive inside the modal and prevent horizontal body overflow
• cover the shared combobox and modal behavior with regression tests

Type of Change

• Bug fix

Testing

• Tested canvas picker dragging, deploy output selection, and modal overflow manually
• bun run lint, bun run check:audits, focused Vitest suites, and affected package typechecks pass

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)