chore: housekeeping — linter & formatter setup

Add .prettierrc.json, .markdownlint.json, .yamllint.yaml, .gitattributes
Run CSharpier, Prettier and markdownlint across the entire codebase.
No logic changes — formatting, using order and line endings only.

HellionChat/Ui/TabIconMapping.cs

@@ -27,7 +27,9 @@ internal static class TabIconMapping
     /// zurück (degraded, kein Crash). Build-Time-Enforcement ist nicht
     /// möglich, weil PickerOptions ohne Dalamud-Reference auskommt.
     /// </summary>
-    private static readonly Dictionary<string, FontAwesomeIcon> GlyphLookup = new(StringComparer.OrdinalIgnoreCase)
+    private static readonly Dictionary<string, FontAwesomeIcon> GlyphLookup = new(
+        StringComparer.OrdinalIgnoreCase
+    )
     {
         ["comment"] = FontAwesomeIcon.Comment,
         ["comments"] = FontAwesomeIcon.Comments,
@@ -65,8 +67,6 @@ internal static class TabIconMapping
         }
 
         var glyph = TabIconGlyphResolver.ResolveGlyphName(tab, autoTellGlyph);
-        return GlyphLookup.TryGetValue(glyph, out var icon)
-            ? icon
-            : FontAwesomeIcon.Hashtag;
+        return GlyphLookup.TryGetValue(glyph, out var icon) ? icon : FontAwesomeIcon.Hashtag;
     }
 }