Incorrect Content-Type Header in Local API Response

[cnadler86]

The Zendure SolarFlow local HTTP API returns JSON data with an incorrect Content-Type header. The API endpoint /properties/report responds with valid JSON data but sets the Content-Type header to text/html instead of application/json (the response body is valid JSON, but the Content-Type header is incorrect.).

This causes issues with HTTP clients that strictly validate Content-Type headers before attempting to parse JSON responses (e.g., aiohttp, axios, fetch with strict mode).

Device Information

• Model: SolarFlow 800 Pro
• Firmware Version: V1.0.23
• API Version: 2

Steps to Reproduce

1. Connect to the SolarFlow device on local network
2. Send HTTP GET request to: http://[device-ip]/properties/report
3. Inspect the response headers

Expected Behavior

The API should return:

HTTP/1.1 200 OK
Content-Type: application/json
Content-Length: [length]

{
  "timestamp": 1768894931,
  "messageId": 6,
  "sn": "EOAxxxxxx",
  ...
}

Actual Behavior

The API returns:

HTTP/1.1 200 OK
Content-Type: text/html
Content-Length: [length]

{
  "timestamp": 1768894931,
  "messageId": 6,
  "sn": "EOAxxxxxx",
  ...
}

[nsmits]

Can confirm; please fix :)