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/m3

@@ -0,0 +1,17 @@
+language variant
+name male3
+gender male
+
+pitch 80 122
+formant 0 100 100 100
+formant 1  96  97 100
+formant 2  96  97 100
+formant 3  96 103 100
+formant 4  95 103 100
+formant 5  95 103 100
+formant 6 100 100 100
+formant 7 100 100 100
+formant 8 100 100 100
+
+consonants 100
+stressAdd 10 10 0 0 0 0 -30 -30