fix: support Unicode characters in form field names

[WTW0313]

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Summary

Fixes inner ticket 2944

Screenshots

Before	After

Checklist

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran make lint && make type-check (backend) and cd web && pnpm exec vp staged (frontend) to appease the lint gods

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.33%. Comparing base (358cf8b) to head (1bafc7a).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #38138      +/-   ##
==========================================
- Coverage   85.38%   85.33%   -0.06%     
==========================================
  Files        5119     4964     -155     
  Lines      262662   258334    -4328     
  Branches    50081    49023    -1058     
==========================================
- Hits       224281   220452    -3829     
+ Misses      34092    33593     -499     
  Partials     4289     4289              

Flag	Coverage Δ
cli	?
dify-ui	94.93% <ø> (ø)
web	85.02% <100.00%> (-0.01%)	⬇️

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[Copilot]

Pull request overview

This PR updates the Markdown form component in the web frontend to accept Unicode characters in form field name attributes, so non-ASCII field names (e.g., Chinese, accented Latin) are not filtered out as “unsafe”.

Changes:

• Expand the “safe field name” regex to allow Unicode letters/marks/numbers.
• Add a unit test ensuring Unicode-named fields are included in JSON submission output.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
web/app/components/base/markdown-blocks/form.tsx	Updates the safe-name validation regex to support Unicode field names.
web/app/components/base/markdown-blocks/tests/form.spec.tsx	Adds a test covering Unicode field-name submission in JSON mode.

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