fix(mcp): trigger OAuth auto-detection probe for empty headers object

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: waleedlatif1

apps/sim/app/api/mcp/servers/route.ts

@@ -113,7 +113,8 @@ export const POST = withRouteHandler(
         const serverId = body.url ? generateMcpServerId(workspaceId, body.url) : generateId()
 
         let resolvedAuthType: 'none' | 'headers' | 'oauth' = body.authType ?? 'headers'
-        if (!body.authType && body.url && !body.headers) {
+        const hasHeaders = body.headers && Object.keys(body.headers).length > 0
+        if (!body.authType && body.url && !hasHeaders) {
           try {
             resolvedAuthType = await detectMcpAuthType(body.url)
             logger.info(`[${requestId}] Probed ${body.url}: authType=${resolvedAuthType}`)