Bug/97623 empty message fix

[sushmi21]

This PR fixes the rendering of empty message bubbles

Success Criteria:

• If the streaming collation is turned off, a message containing only an escape sequence should not be rendered irrespective of the render markdown setting. (There should not be empty message bubble)

Te test:

• Check the example added for escape sequence check in the demo page > Text Messages tab.
• Please note that there is a regression in rendering number 0 message, so you will see one empty bubble.

[Copilot]

Pull request overview

This PR fixes an issue where message bubbles containing only whitespace or escape sequences were being rendered as empty bubbles. The fix extracts the escape sequence detection logic into a reusable utility function and updates the message matching logic to properly handle these cases.

Key Changes:

• Introduced a utility function to detect strings containing only escape sequences/whitespace
• Updated message matching logic to filter out escape-sequence-only messages when streaming collation is disabled
• Added a test case demonstrating the fix for messages with only newlines and spaces

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/utils.ts	Added isOnlyEscapeSequence utility function to detect whitespace-only strings
src/matcher.ts	Updated message validation to use the new utility and removed redundant markdown check
test/demo.tsx	Added test case for whitespace-only message bubble scenario

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[vj-venkatesan]

Regex looks good. Although I don't understand why the empty bubble shows up when your text is " \n\n"