Fix render-phase update in RenderSubFields

memory-bank/change-log.md

@@ -3447,3 +3447,29 @@ Validation:
 Follow-ups:
 
 - Continue bounded Phase 2 slices; when touching field components, prefer top-level computed hook-backed values reused across conditional branches.
+
+---
+
+### CL-096: 22500 `RenderSubFields` render-phase update warning hotfix
+
+date: 2026-04-07
+author: Cline
+scope: `components/elements/fields/renderSubFields.js`
+type: change
+rationale: Fix React warning about updating parent-connected state during `RenderSubFields` render.
+impact: No intended behavior change; initial empty FieldArray row initialization moved out of render phase to effect phase to satisfy React rendering constraints.
+status: completed
+
+Summary:
+
+- Root cause: `fields.length == 0 && fields.push({})` executed inside render, triggering state updates while rendering `RenderSubFields`.
+- Fix: moved initial row insertion into `useEffect`, guarded by `fields.length === 0`.
+- Preserved existing UX intent: ensure at least one subfield row appears when array starts empty.
+
+Validation:
+
+- `npx eslint components/elements/fields/renderSubFields.js` -> pass
+
+Follow-ups:
+
+- Keep redux-form `fields.push/remove` calls event/effect-driven (not render-driven) in future slices.