Fix chat endpoint - use text() instead of json()

- wws Response object may not have json() method
- Parse response manually with JSON.parse

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

chat/index.js

@@ -45,7 +45,14 @@ const handler = async (request) => {
       })
     })
 
-    const result = await n8nResponse.json()
+    // Use text() and parse manually (json() may not be available in wws)
+    const responseText = await n8nResponse.text()
+    let result
+    try {
+      result = JSON.parse(responseText)
+    } catch (e) {
+      result = { text: responseText }
+    }
 
     let response = new Response(JSON.stringify({
       success: true,