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-c6-test-1.yaml

@@ -46,7 +46,7 @@ esp32:
 logger:
   hardware_uart: USB_SERIAL_JTAG
   logs:
-    component: ERROR 
+    component: ERROR
 
 # web_server:
 #   port: 80
@@ -114,4 +114,4 @@ light:
             state = !state;
 
 packages:
-  common: !include common/common.yaml
+  common: !include common/common.yaml