site.yaml wordmark_height; raster logos keep their colors

Custom wordmark sizing per site (0.5-6 rem, clamped at render), and
the light-theme invert now applies only to .svg wordmarks - the
white-stroke house style - so a client's raster logo is never
recolored.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y42TyF8Zu7NGRR2893vNcZ

style/main.css

@@ -99,10 +99,10 @@
     --hero-glow: rgba(246, 245, 241, 0.85);
   }
 
-  /* The wordmark SVG is a hardcoded white stroke (also used raw in
-     dark contexts elsewhere) - flip it to ink here rather than fork
-     the asset. */
-  .wordmark img {
+  /* The house wordmark SVG is a hardcoded white stroke (also used
+     raw in dark contexts elsewhere) - flip it to ink here rather
+     than fork the asset. A content-provided logo keeps its colors. */
+  .wordmark-house img {
     filter: invert(0.92);
   }