Agregar campo username a User entity y DTO

- Columna username (unique, nullable) en auth.users
- Campo username en CreateUserDto y UpdateUserDto

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tts/piper/espeak-ng-data/voices/!v/m7

@@ -0,0 +1,17 @@
+language variant
+name male7
+gender male
+
+pitch  75 125
+
+formant 0 100 125 100
+formant 1 100 90 80
+formant 2 100 70 90
+formant 3 100 60 90
+formant 4 100 60 90
+formant 5  75 50 90
+formant 6  90 50 100
+formant 7 100 50 100
+formant 8 100 50 100
+voicing 155
+