[knowledge] Enable No ascii chars in knowledge

[jolestar]

Relates to

#2376

Risks

Low

Background

What does this PR do?

• The issue was fixed by updating the regex pattern to use Unicode properties:
• Changed from: /[^a-zA-Z0-9\s\-_./:?=&]/g
• To: /[^\p{L}\p{N}\s\-_./:?=&]/gu
• Added 'u' flag for Unicode support
• Used \p{L} to match any kind of letter from any language
• Used \p{N} to match any kind of numeric character
• The fix allows the function to properly handle multilingual content while maintaining the original sanitization goals.

What kind of change is this?

Bug fixes (non-breaking change which fixes an issue)

Documentation changes needed?

My changes do not require a change to the project documentation.

Testing

Where should a reviewer start?

Detailed testing steps

Add a unit test.

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

[github-actions]

Hi @jolestar! Welcome to the elizaOS community. Thanks for submitting your first pull request; your efforts are helping us accelerate towards AGI. We'll review it shortly. You are now an elizaOS contributor!

[wtfsayo]

please do it via env flag