issues with base url generation

Behind a tls-terminating proxy like traefik, a https job submission to the proxy returns links to http endpoints, not https.

Some sort of x-forwarded-proto/host support from trusted proxies or an `--external-base-url` argument might be helpful there, otherwise even if there is a http path, most clients see it as a different origin and drop the bearer token.

```
POST https://comfy-proxy.example/api/v2/jobs HTTP/1.1
Host: comfy-proxy.example
Authorization: Bearer
Content-Type: application/json
Idempotency-Key:

{
"workflow": {
"": ""
}
}

HTTP/1.1 201 Created
Content-Type: application/json

{
"id": "",
"status": "queued",
"outputs": [],
"urls": {
"self": "http://comfy-proxy.example/api/v2/jobs/",
"events": "http://comfy-proxy.example/api/v2/jobs//events",
"cancel": "http://comfy-proxy.example/api/v2/jobs//cancel"
}
}
```