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/quincy

@@ -0,0 +1,20 @@
+language variant
+name Quincy
+
+pitch  67 100
+
+formant 0 85 108 106 3
+formant 1 97 110 56
+formant 2 96 80 60
+formant 3 101 50 50
+formant 4 110 33 55
+formant 5 110 22 65
+formant 6 77 60 60 65
+formant 7 66 0 100
+formant 8 100 0 100
+voicing 99
+consonants 66 90
+
+roughness 0
+tone 600 170 1200 100 2000 70
+stressAmp 16 16 24 20 20 16 28 24