Feat/form validation feedback

[Devadakene]

Closes #231

Summary

Enhances the TaskSubmissionForm and SendXLMForm with real-time inline validation, visual error states, success indicators, and accessible error announcements to reduce failed submissions and improve user confidence.

Changes

• Extracted validation logic into shared Zod schemas in frontend/src/schemas/task.ts and frontend/src/schemas/wallet.ts.
• Created a new reusable FormField component (frontend/src/components/common/FormField.tsx) with dynamic validation display (red/green borders on blur).
• Refactored TaskSubmissionForm and SendXLMForm to integrate react-hook-form error handling with mode: 'onBlur'.
• Disabled form submit buttons until all fields successfully pass validation.
• Added aria-live="polite" regions for screen readers to dynamically announce validation errors.
• Added a dynamic character counter (remaining/max) for the task prompt field.
• Implemented success feedback mechanisms (button state changes + success toasts) on form submission.
• Added test coverage for the new validation display logic (FormField.test.tsx).

Testing

• Validation on Blur: Tab through empty or incorrectly formatted fields to verify that error messages (with AlertCircle icons) and red borders appear immediately on blur.
• Valid States: Enter valid data and verify that fields receive a green border on blur.
• Form Submission: Verify that the Submit button remains disabled until all inputs are valid.
• Success Feedback: Submit a valid task and payment to verify the success toast and distinct button state changes appear.

Related Issue

• #[Issue Number]

Checklist

• Tests pass
• Lint is clean
• Documentation updated if needed

[vercel]

@Devadakene is attempting to deploy a commit to the Jaja's projects Team on Vercel.

A member of the Team first needs to authorize it.

[devJaja]

@Devadakene
Resolve the conflicts, also fix the CI checks

[devJaja]

@Devadakene
The CI frontend is still failing