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/f5

@@ -0,0 +1,23 @@
+language variant 
+name female5
+gender female 
+
+pitch 160 228
+roughness 0
+
+formant 0 105  80 150 
+formant 1 110  80 160 
+formant 2 110  70 150 
+formant 3 110  70 150 
+formant 4 115  80 200 
+formant 5 115  80 100 
+formant 6 110  70 150 
+formant 7 110  70 100 
+formant 8 110  70 150 
+
+stressAdd 0 0 -10 -10 0 0 10 40 
+breath 0 4  6   6   6   6  0 10 
+echo 140 10 
+voicing 75 
+consonants 150 150
+breathw 150 150 200 200 400 400 600 600