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-air-office-r.yaml

@@ -10,7 +10,7 @@ esphome:
   friendly_name: ${name}
   area: ${area}
   comment: ${comment}
-  
+
 esp32:
   variant: esp32
   framework:
@@ -18,7 +18,7 @@ esp32:
 
 packages:
   common: !include common/common.yaml
-  
+
 i2c:
   # - id: i2c0
   sda: 32
@@ -109,4 +109,4 @@ sensor:
     uart_id: particle_uart
     update_interval: 20s
     pm_2_5:
-      name: Particulate Matter 2.5µm Concentration
+      name: Particulate Matter 2.5µm Concentration