fix(siliconflow): update baseUrl .cn -> .com + curate verified model list

Switch all siliconflow endpoints from api.siliconflow.cn to .com (chat,
validate, test, models) — the .cn host rejected valid .com-issued keys.
Replace the model list with 13 strong models verified live against the API.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/app/api/providers/[id]/models/route.js

@@ -232,7 +232,7 @@ const PROVIDER_MODELS_CONFIG = {
   cerebras: createOpenAIModelsConfig("https://api.cerebras.ai/v1/models"),
   cohere: createOpenAIModelsConfig("https://api.cohere.ai/v1/models"),
   nebius: createOpenAIModelsConfig("https://api.studio.nebius.ai/v1/models"),
-  siliconflow: createOpenAIModelsConfig("https://api.siliconflow.cn/v1/models"),
+  siliconflow: createOpenAIModelsConfig("https://api.siliconflow.com/v1/models"),
   hyperbolic: createOpenAIModelsConfig("https://api.hyperbolic.xyz/v1/models"),
   ollama: createOpenAIModelsConfig("https://ollama.com/api/tags"),
   // ollama-local: url resolved dynamically below via providerSpecificData.baseUrl

src/app/api/providers/[id]/test/testUtils.js

@@ -527,7 +527,7 @@ async function testApiKeyConnection(connection, effectiveProxy = null) {
         return { valid: res.ok, error: res.ok ? null : "Invalid API key" };
       }
       case "siliconflow": {
-        const res = await fetchWithConnectionProxy("https://api.siliconflow.cn/v1/models", { headers: { Authorization: `Bearer ${connection.apiKey}` } }, effectiveProxy);
+        const res = await fetchWithConnectionProxy("https://api.siliconflow.com/v1/models", { headers: { Authorization: `Bearer ${connection.apiKey}` } }, effectiveProxy);
         return { valid: res.ok, error: res.ok ? null : "Invalid API key" };
       }
       case "hyperbolic": {