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/f1

@@ -0,0 +1,18 @@
+language variant
+name female1
+gender female 70
+
+pitch 140 200
+flutter 8
+roughness 4
+formant 0 115  80 150
+formant 1 120  80 180
+formant 2 100  70 150  150
+formant 3 115  70 150
+formant 4 110  80 150
+formant 5 110  90 150
+formant 6 105  80 150
+formant 7 110  70 150
+formant 8 110  70 150
+
+stressAdd -10 -10 -20 -20 0 0 40 60