feat(transformers): support meta.indent for indent guides

[L33Z22L11]

Description

The transformerRenderIndentGuides from @shikijs/transformers previously only parsed the this.options.meta?.__raw string to get the indent value. This PR adds support for reading the pre-parsed this.options.meta?.indent configuration and optimizes the indent value validation logic (skips processing if the value is non-numeric('false') or ≤ 0).

Linked Issues

Additional context

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 88.24%. Comparing base (b536e4d) to head (5b10930).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...nsformers/src/transformers/render-indent-guides.ts	0.00%	6 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1087      +/-   ##
==========================================
- Coverage   88.26%   88.24%   -0.03%     
==========================================
  Files          74       74              
  Lines        3290     3291       +1     
  Branches      943      945       +2     
==========================================
  Hits         2904     2904              
- Misses        341      344       +3     
+ Partials       45       43       -2     

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