feat(workflow-form): authoring mode for building the Form View

[yangzhang75]

Task Summary

Add the authoring side of the same page — where the author builds the form.

• toggleAuthoring toggle; expose/rename which settings readers fill in
• jump to the operator canvas via openRegularCanvas (Edit operators →)
• prune bindings whose operator or property no longer exists
• operator attribution ("From X" / "Set on X") shows only while authoring

Task Type

• Refactor / Cleanup
• DevOps / Deployment / CI
• Testing / QA
• Documentation
• Performance
• Other

[yangzhang75]

/parent-issue: #8011

[yangzhang75]

/take