Add voice selection control

Expose a voice selector next to the save button and pass the choice to TTS so pyttsx3 can prefer a female voice.

server/main.py

@@ -48,6 +48,7 @@ templates = Jinja2Templates(directory=str(CLIENT_DIR / "templates"))
 
 class TtsCreateRequest(BaseModel):
     text: str
+    voice: str | None = None
 
 
 class TtsDeleteRequest(BaseModel):
@@ -125,6 +126,7 @@ def api_list_tts():
 @app.post("/api/tts")
 def api_create_tts(payload: TtsCreateRequest):
     text = (payload.text or "").strip()
+    voice = (payload.voice or "").strip().lower()
     if len(text) < 11:
         raise HTTPException(status_code=400, detail="텍스트는 11글자 이상이어야 합니다.")
 
@@ -137,7 +139,7 @@ def api_create_tts(payload: TtsCreateRequest):
     mp3_path = RESOURCES_DIR / filename
 
     try:
-        text_to_mp3(text=text, mp3_path=str(mp3_path))
+        text_to_mp3(text=text, mp3_path=str(mp3_path), voice=voice)
     except Exception as exc:
         logger.exception("TTS 생성 실패")
         delete_item_by_id(tts_id)