fix(APP-593): Fix crash when removing early items from watched field arrays

[milosh86]

Description

Fixes a crash that occurred when removing items from the middle of an uploaded JSON action list (or similar watched field arrays). The root cause was a stale-data race between useWatch and useFieldArray: immediately after remove(), useWatch still returns the old (longer) array while fields has already been updated, causing the merge map to override fieldArray items with wrong items from watched list, while id/key of items is kept the same.

Fix: Before merging fields and watchFieldArray, check that their lengths match. If they don't (stale frame), skip the watch data for that render and preserve the field.id from the source-of-truth useFieldArray. Applied to:

• CreateProposalFormActions (JSON upload actions)
• GovernanceStageBodiesField (governance stage bodies)
• TokenSetupMembershipCreateToken (token member list)

Resolves APP-593.

Type of Change

• Patch: Bug fix (non-breaking change which fixes an issue)

Developer Checklist:

• Manually smoke tested the functionality in a preview or locally
• Confirmed there are no new warnings or errors in the browser console
• (For User Stories only) Double-checked that all Acceptance Criteria are satisfied
• Confirmed there are no new warnings on automated tests
• Merged and published any dependent changes in downstream modules
• Selected the correct base branch
• Commented the code in hard-to-understand areas
• Followed the code style guidelines of this project
• Reviewed that the Files Changed in Github's UI reflect my intended changes
• Confirmed the pipeline checks are not failing

Review Checklist:

• (For User Stories only) Tested in a preview or locally that all Acceptance Criteria are satisfied
• Confirmed that changes follow the code style guidelines of this project

[linear]

APP-593 App crashes when removing early actions from JSON upload

[github-actions]

🚀 Preview Deployment: View Here

[github-actions]

E2E Smoke Results

Base URL	https://app-next-8d30gyrtv-aragon-app.vercel.app
Suite	smoke
Playwright result	✅ passed
Summary	43 passed, 1 skipped
GitHub job	✅ completed
Run	#3975

[thekidnamedkd]

Looks good!✨ I would maybe just keep the var names the same as much as possible and not past tense where possible

[milosh86]

Looks good!✨ I would maybe just keep the var names the same as much as possible and not past tense where possible

yeah, makes sense, I'll update

[thekidnamedkd]

LGTM ✨