feat: improve voice studio alpha recovery flow

backend/app/core/config.py

@@ -82,6 +82,18 @@ class Settings(BaseSettings):
         "zh",
         description="Preferred language hint for voice transcription",
     )
+    voice_turn_max_upload_bytes: int = Field(
+        5 * 1024 * 1024,
+        description="Maximum accepted upload size in bytes for one voice turn audio file",
+    )
+    voice_session_default_list_limit: int = Field(
+        8,
+        description="Default number of recent voice sessions returned to the client",
+    )
+    voice_session_max_list_limit: int = Field(
+        20,
+        description="Maximum number of recent voice sessions returned to the client",
+    )
     story_audio_cache_ttl_days: int = Field(
         30,
         description="TTL in days before cached story audio is pruned",