Prometheus service type doesn't apply basic_auth credentials

[psaghelyi]

Description

The Prometheus service type doesn't include the Authorization header when making API requests, even when basic_auth is configured. This differs from the Traefik service type which correctly applies basic_auth.

Homer version

v25.11.1

Configuration

- name: "Prometheus"
  type: "Prometheus"
  url: "https://prometheus.example.com"
  basic_auth: "admin:password"

- name: "Traefik Dashboard"
  type: "Traefik"
  url: "https://traefik.example.com"
  basic_auth: "admin:password"

Observed behavior

Network requests show:

• Traefik: Sends OPTIONS preflight → GET with Authorization header → ✅ 200 OK
• Prometheus: Sends GET without Authorization header → ❌ 401 Unauthorized

Expected behavior

Both service types should include the Authorization header when basic_auth is configured.

Additional context

• Server correctly returns CORS headers on 401 responses (Access-Control-Allow-Origin, Access-Control-Allow-Credentials: true)
• This is NOT the CORS preflight issue documented in PR Fix prometheous inactive alerts and print version #949 - the problem is that the Authorization header is never sent at all for the Prometheus type
• The Traefik component correctly triggers a CORS preflight by including the Authorization header