fix(NcModal): properly handle modal name size

[susnux]

☑️ Resolves

• When the width is small the name must be ellipsed and not overflow any action (e.g. the play buttton!).
• The name must be centered if wide enough (it was not because padding was incorrectly calculated).

🖼️ Screenshots

Bildschirmaufnahme_20260227_163610.webm

🏁 Checklist

• ⛑️ Tests are included or are not applicable
• 📘 Component documentation has been extended, updated or is not applicable
• 2️⃣ Backport to stable8 for maintained Vue 2 version or not applicable

[codecov]

Codecov Report

❌ Patch coverage is 20.00000% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 52.75%. Comparing base (81c5924) to head (632e71b).
⚠️ Report is 16 commits behind head on main.

Files with missing lines	Patch %	Lines
src/components/NcModal/NcModal.vue	20.00%	5 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8263      +/-   ##
==========================================
- Coverage   52.84%   52.75%   -0.10%     
==========================================
  Files         103      103              
  Lines        3351     3361      +10     
  Branches      977      979       +2     
==========================================
+ Hits         1771     1773       +2     
- Misses       1332     1337       +5     
- Partials      248      251       +3     

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[susnux]

/backport to stable8

[Antreesy]

Looks fine from the deployed page