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/Reed

@@ -0,0 +1,15 @@
+language variant
+name Reed
+klatt 6
+consonants 85 85
+voicing 130
+breath 45
+
+pitch 85 135
+
+formant 1 72 100 90 90
+formant 2 83 100 75 180
+formant 3 98 100 100 90
+formant 4 98 100 90
+formant 5 100 100 90
+