feat(provider): 添加厂商预设与模型发现接口

backend/app/providers/factory.py

@@ -1,4 +1,4 @@
-from app.contracts import ModelCapability, ProviderConfig, ProviderType
+from app.contracts import ModelCapability, ProviderConfig, ProviderPreset, ProviderType
 from app.providers.base import ModelProvider
 from app.providers.credentials import CredentialResolver
 from app.providers.ollama import OllamaProvider
@@ -27,6 +27,30 @@ class ProviderFactory:
             return OllamaProvider(config.base_url or "http://127.0.0.1:11434")
         raise UnsupportedProviderError(config.provider_type.value)
 
+    @staticmethod
+    def presets() -> list[ProviderPreset]:
+        return [
+            ProviderPreset(
+                preset_id="openai",
+                name="OpenAI",
+                provider_type=ProviderType.openai_chat,
+                base_url="https://api.openai.com/v1",
+            ),
+            ProviderPreset(
+                preset_id="deepseek",
+                name="DeepSeek",
+                provider_type=ProviderType.openai_compatible,
+                base_url="https://api.deepseek.com",
+            ),
+            ProviderPreset(
+                preset_id="ollama",
+                name="Ollama",
+                provider_type=ProviderType.ollama,
+                base_url="http://127.0.0.1:11434",
+                requires_credential=False,
+            ),
+        ]
+
     @staticmethod
     def capabilities(provider_type: ProviderType) -> list[ModelCapability]:
         if provider_type in {