fix: Content field styling preserved

[Hemant-dbit]

Description

Fixes #489

Text styling (color, italic, bold, underline) is now preserved when editing text through the Content field in the properties panel.

Problem

Previously, editing text via the Content field would strip all formatting, leaving only plain text.

Solution

• Modified TextBlock.vue to detect plain text input and preserve existing HTML styling
• Extended TipTap's TextStyle to handle inline style attributes
• When plain text is entered, only the text content is updated while keeping all HTML tags intact

Testing

1. Add text block
2. Apply styling (color, italic, bold, etc.)
3. Edit text in Content field
4. Styling is preserved

Before

My.Page._.Builder.-.Google.Chrome.2026-02-15.19-57-20.mp4

After

My.Page._.Builder.-.Google.Chrome.2026-02-15.20-00-37.mp4

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 60.61%. Comparing base (9617319) to head (fd6c58d).
⚠️ Report is 4 commits behind head on develop.

Additional details and impacted files

@@           Coverage Diff            @@
##           develop     #492   +/-   ##
========================================
  Coverage    60.61%   60.61%           
========================================
  Files           28       28           
  Lines         2722     2722           
========================================
  Hits          1650     1650           
  Misses        1072     1072           

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[surajshetty3416]

@Hemant-dbit Can you also a video demonstrating the issue vs fix?

[Hemant-dbit]

@surajshetty3416 yes sure

[Hemant-dbit]

@surajshetty3416 I have added videos as well demonstrating before and after the issue