[FE-17] Build DisputeSubmissionForm

[mftee]

Problem

The dispute submission backend endpoint exists (BE-06) but there is no frontend form. Users who want to raise a dispute about a flagged document have no way to do so through the UI.

Proposed Solution

Create a DisputeSubmissionForm component inside frontend/module/disputes/submit/ that collects dispute details and submits them to the backend.

Acceptance Criteria

• Renders a document selector (dropdown populated from the user's documents), a disputeType selector, and a description textarea
• The document selector pre-selects the document if a documentId prop is passed (e.g. when navigating from a document detail page)
• Description field requires a minimum of 20 characters and shows a live character count
• Includes an optional file attachment input (single file, PDF/PNG/JPEG, max 10MB) that uploads evidence via the DisputeEvidenceUploadController (BE-33)
• On submit, calls POST /api/module/disputes and on success redirects to the dispute list page with a success message
• Shows inline validation errors for empty required fields
• All component files live inside frontend/module/disputes/submit/

[demilade18-git]

@demilade18-git has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hello,

I'd be happy to work on this issue.

I took some time to review the task and it looks like a good fit for my experience. I enjoy contributing to open-source projects, following established patterns, and making sure changes are well-tested and easy to maintain.

If the issue is still open, I'd appreciate the opportunity to contribute.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @demilade18-git to this issue.

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Congratulations, @demilade18-git! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

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This issue has been completed by @demilade18-git as part of the Stellar Wave Program's 5th Wave 🥳

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