fix(provider): 修复DeepSeek开发凭据解析

backend/app/providers/credentials.py

@@ -10,8 +10,17 @@ class CredentialResolver(Protocol):
 class EnvironmentCredentialResolver:
     """解析由桌面 Host 注入 Sidecar 进程的临时凭证上下文。"""
 
+    _development_aliases = {
+        "openai": "OPENAI_API_KEY",
+        "deepseek": "DEEPSEEK_API_KEY",
+    }
+
     def resolve(self, credential_id: str | None) -> str | None:
         if not credential_id:
             return None
         normalized = re.sub(r"[^A-Za-z0-9]", "_", credential_id).upper()
-        return os.getenv(f"AINOTE_CREDENTIAL_{normalized}")
+        injected = os.getenv(f"AINOTE_CREDENTIAL_{normalized}")
+        if injected:
+            return injected
+        alias = self._development_aliases.get(credential_id.lower())
+        return os.getenv(alias) if alias else None