fix(studio): remove 50-model cap from test endpoint response

Services like PPIO (71 models) and SiliconFlow (111 models) were
truncated to 50. Return the full list.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/studio/src/api/server.ts

@@ -1003,7 +1003,7 @@ export function createStudioServer(initialConfig: ProjectConfig, root: string) {
     return c.json({
       ok: true,
       modelCount: probe.models.length,
-      models: probe.models.slice(0, 50),
+      models: probe.models,
       selectedModel: probe.selectedModel,
       detected: {
         apiFormat: probe.apiFormat,