Remove Edge-TTS provider due to HuggingFace Spaces incompatibility

Edge-TTS has persistent asyncio event loop conflicts in containerized
environments that cannot be resolved. Removing it simplifies the codebase
and eliminates all asyncio errors.

Changes:
- Removed EdgeTTSProvider class and all Edge-TTS code
- Removed edge-tts from dependencies (pyproject.toml, requirements.txt)
- Updated default TTS provider to OpenAI TTS
- Removed asyncio and threading imports (no longer needed)
- Updated comments and documentation

Remaining TTS providers (both fully working on HF Spaces):
✓ OpenAI TTS (paid, high quality, default)
✓ gTTS (free, good quality)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

config.py

@@ -198,7 +198,6 @@ class VoiceConfig:
     # Note: Voice choices are dynamically loaded based on selected TTS provider
     # See voice_handler.py for provider-specific voice lists:
     # - OpenAI TTS: alloy, echo, fable, onyx, nova, shimmer
-    # - Edge-TTS: en-US-AriaNeural, en-US-GuyNeural, en-US-JennyNeural, etc.
     # - gTTS: default
 
     # OpenAI TTS voices (kept for reference, not used in UI)

pyproject.toml

@@ -8,7 +8,6 @@ authors = [
 readme = "README.md"
 requires-python = ">=3.10"
 dependencies = [
-    "edge-tts>=7.2.3",
     "gradio>=5.0.0",
     "gtts>=2.5.4",
     "huggingface-hub>=1.1.4",

requirements.txt

@@ -2,7 +2,6 @@ gradio
 huggingface_hub
 python-dotenv
 openai
-edge-tts
 openai-whisper
 gtts
 langdetect

voice_handler.py

@@ -9,11 +9,8 @@ import tempfile
 from abc import ABC, abstractmethod
 from pathlib import Path
 from typing import Optional, List, Dict
-import asyncio
-import threading
 
 # Import voice processing libraries
-# Note: edge_tts is imported lazily to avoid asyncio event loop issues at module import time
 from openai import OpenAI
 import whisper
 from gtts import gTTS
@@ -50,19 +47,6 @@ class VoiceConfig:
 
     # TTS Provider definitions
     TTS_PROVIDERS = {
-        "Edge-TTS (Free)": {
-            "id": "edge_tts",
-            "cost_tier": "free",
-            "cost_per_1k_chars": 0.0,
-            "requires_api_key": False,
-            "voices": [
-                "en-US-AriaNeural",
-                "en-US-GuyNeural",
-                "en-US-JennyNeural",
-                "en-GB-SoniaNeural",
-                "en-GB-RyanNeural",
-            ]
-        },
         "OpenAI TTS": {
             "id": "openai_tts",
             "cost_tier": "medium",
@@ -81,8 +65,8 @@ class VoiceConfig:
 
     # Default selections
     DEFAULT_STT = "OpenAI Whisper API"
-    DEFAULT_TTS = "Edge-TTS (Free)"
-    DEFAULT_TTS_VOICE = "en-US-JennyNeural"
+    DEFAULT_TTS = "OpenAI TTS"
+    DEFAULT_TTS_VOICE = "nova"
 
 
 # ============================================================================
@@ -188,61 +172,6 @@ class LocalWhisperSTT(STTProvider):
 # TTS Provider Implementations
 # ============================================================================
 
-class EdgeTTSProvider(TTSProvider):
-    """Microsoft Edge TTS implementation (free)."""
-
-    def __init__(self, voice: str = "en-US-JennyNeural"):
-        self.voice = voice
-
-    def synthesize(self, text: str, output_path: Optional[str] = None) -> str:
-        """Synthesize speech using Edge TTS."""
-
-        if output_path is None:
-            output_path = os.path.join(tempfile.gettempdir(), f"tts_{os.getpid()}.mp3")
-
-        try:
-            # Import edge_tts lazily to avoid asyncio issues at module import time
-            import edge_tts
-
-            # Edge TTS requires async
-            async def _synthesize():
-                communicate = edge_tts.Communicate(text, self.voice)
-                await communicate.save(output_path)
-
-            # Run async code in a separate thread to completely isolate event loop
-            # This prevents conflicts with Gradio/HuggingFace Spaces event loops
-            exception_holder = [None]
-
-            def run_in_thread():
-                try:
-                    loop = asyncio.new_event_loop()
-                    asyncio.set_event_loop(loop)
-                    try:
-                        loop.run_until_complete(_synthesize())
-                    finally:
-                        loop.close()
-                except Exception as e:
-                    exception_holder[0] = e
-
-            thread = threading.Thread(target=run_in_thread)
-            thread.start()
-            thread.join(timeout=30)  # 30 second timeout
-
-            if thread.is_alive():
-                raise Exception("Edge TTS synthesis timed out")
-
-            if exception_holder[0]:
-                raise exception_holder[0]
-
-            return output_path
-        except Exception as e:
-            raise Exception(f"Edge TTS synthesis failed: {str(e)}")
-
-    def get_available_voices(self) -> List[str]:
-        """Get available Edge TTS voices."""
-        return VoiceConfig.TTS_PROVIDERS["Edge-TTS (Free)"]["voices"]
-
-
 class OpenAITTSProvider(TTSProvider):
     """OpenAI TTS implementation."""
 
@@ -346,9 +275,7 @@ def create_tts_provider(provider_name: str, voice: Optional[str] = None) -> TTSP
     if voice is None:
         voice = provider_info["voices"][0]
 
-    if provider_id == "edge_tts":
-        return EdgeTTSProvider(voice=voice)
-    elif provider_id == "openai_tts":
+    if provider_id == "openai_tts":
         return OpenAITTSProvider(voice=voice)
     elif provider_id == "gtts":
         return GTTSProvider(voice=voice)