feat(workflow-form): render nested and array sub-field inputs #8022

Task Summary

(Repurposed: the standalone author-instruction task folded into the run PR #8023; this issue now tracks the sub-field slice split out of the render PR #8370.)

On top of the top-level input rendering (#8370), render the sub-fields of an exposed nested (object) or repeated (array) property, and apply the author's per-sub-field setup. Writing a filled-in value back to its operator is already handled by #8370 (formly's model carries the nested value); this slice is the sub-field rendering and overrides.

• childPath / arrayItemOf helpers: key an override by field path (array indices dropped, so one entry covers every row) and resolve a repeated section's row template, whether formly gives it as a value or a builder function
• walk the built formly field and its sub-fields, dropping the operator schema's own per-field descriptions (author notes about the operator, not guidance to a form reader) and applying the author's stored per-sub-field overrides (rename, hide)
• a repeated section builds its row template on demand, so wrap the builder to decorate every row formly ever creates

Task Type

• Other