refactor: Improve code readability and structure across TTS modules

app/services/tts/base.py

@@ -1,14 +1,16 @@
 """Base TTS provider interface."""
 
 from abc import ABC, abstractmethod
-from typing import Any
+
+# Type alias for TTS options
+TTSOptions = dict[str, str | bool | int | float]
 
 
 class TTSProvider(ABC):
     """Abstract base class for TTS providers."""
 
     @abstractmethod
-    async def generate_speech(self, text: str, **options: Any) -> bytes:
+    async def generate_speech(self, text: str, **options: str | bool | float) -> bytes:
         """Generate speech from text with provider-specific options.
 
         Args:
@@ -25,7 +27,7 @@ class TTSProvider(ABC):
         """Return list of supported language codes."""
 
     @abstractmethod
-    def get_option_schema(self) -> dict[str, Any]:
+    def get_option_schema(self) -> dict[str, dict[str, str | list[str] | bool]]:
         """Return schema for provider-specific options."""
 
     @property