Fix startup issues for HF Spaces

- Rename app_v2.py → app.py (HF Spaces requirement)
- Update config.py to not fail on missing API keys
- Add graceful warnings instead of errors
- App will now start and show friendly messages in UI
- Added has_any_api_key() and get_available_providers() helpers

src/config.py

@@ -101,15 +101,37 @@ class Config:
 
     def _validate(self):
         """Validate configuration and API keys"""
+        # Don't fail startup on missing keys - just warn
+        # The UI will show appropriate error messages when features are used
         if not self.anthropic_api_key and self.model.primary_provider == "anthropic":
-            raise ValueError("ANTHROPIC_API_KEY not found in environment")
+            print("⚠️  Warning: ANTHROPIC_API_KEY not found in environment")
+            print("   Configure API keys in Settings → Variables and secrets")
 
         if not self.google_api_key and self.model.memory_provider == "google":
-            raise ValueError("GOOGLE_API_KEY not found in environment for memory model")
+            print("⚠️  Warning: GOOGLE_API_KEY not found for memory model")
 
         # Ensure database directory exists
         self.database.ensure_db_dir()
 
+    def has_any_api_key(self) -> bool:
+        """Check if at least one API key is configured"""
+        return bool(
+            self.anthropic_api_key or
+            self.openai_api_key or
+            self.google_api_key
+        )
+
+    def get_available_providers(self) -> list[str]:
+        """Get list of providers with configured API keys"""
+        providers = []
+        if self.anthropic_api_key:
+            providers.append("anthropic")
+        if self.openai_api_key:
+            providers.append("openai")
+        if self.google_api_key:
+            providers.append("google")
+        return providers
+
     def get_model_config(self, task_type: str = "balanced") -> dict:
         """Get model configuration for specific task type"""
         temp_map = {