fix #13873 [DarkMode]: TabControl doesn't render tab titles correctly when SizeMode = Fixed

[Epica3055]

Fixes #13873

Root cause

When TabSizeMode is set , it will trigger RecreateHandle, which in turn will trigger OnHandleCreated, ApplyDarkModeOnDemand, and eventually PInvoke.SetWindowTheme.

I think this might break the normal code flow. Setting TabSizeMode advances some procedures.

Proposed changes

• when TabSizeMode is set and if it's dark mode and handle is created then RecreateHandle

Screenshots

Before

After

Test methodology

• manual

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Codecov Report

❌ Patch coverage is 75.00000% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 77.12514%. Comparing base (04dbda2) to head (6ba607b).
⚠️ Report is 12 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #13878         +/-   ##
===================================================
+ Coverage   77.11833%   77.12514%   +0.00681%     
===================================================
  Files           3273        3273                 
  Lines         644931      644922          -9     
  Branches       47692       47695          +3     
===================================================
+ Hits          497360      497397         +37     
+ Misses        143900      143850         -50     
- Partials        3671        3675          +4     

Flag	Coverage Δ
Debug	77.12514% <75.00000%> (+0.00681%)	⬆️
integration	18.99162% <0.00000%> (+0.00303%)	⬆️
production	51.96533% <75.00000%> (+0.01447%)	⬆️
test	97.41256% <ø> (ø)
unit	49.37754% <75.00000%> (+0.01231%)	⬆️

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Pull Request Overview

This PR fixes a bug where TabControl doesn't render tab titles correctly when SizeMode is set to Fixed in dark mode. The issue occurs because setting TabSizeMode triggers RecreateHandle, which interferes with the dark mode rendering flow.

• Adds conditional logic to only call RecreateHandle when necessary in dark mode scenarios
• Ensures proper handle recreation when dark mode is enabled and the handle already exists