Fix trailing spaces and missing newlines in all mcu-*.yaml files

Bulk cleanup: remove trailing whitespace and ensure files end with a
newline. Structural issues (indentation, bracket spacing) left for
per-file fixes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

mcu-clock-living-room.yaml

@@ -76,7 +76,7 @@ display:
         if ((i % 2) == 0)
           it.print("8 8 ");
         else
-          it.print(" 8 8");      
+          it.print(" 8 8");
       } else {
         if (((i / 10) % 2) == 0) {
           //it.set_intensity(7);