docs(api): document inbound_mtls_profile for HTTP routes in swagger

Clarify OpenAPI and the `Route` field: HTTP-based routes only, must
match a configured `inbound_mtls_profiles` entry, and ignored when
`entrypoint.inbound_mtls_profile` is set. Reorder `load_avg_5m` in the
host metrics schema alongside the other load average fields.

internal/api/v1/docs/swagger.json

@@ -5442,6 +5442,7 @@
           "x-nullable": true
         },
         "inbound_mtls_profile": {
+          "description": "HTTP-based routes only: must match a configured inbound_mtls_profiles entry and is ignored when entrypoint.inbound_mtls_profile is set",
           "type": "string",
           "x-nullable": false,
           "x-omitempty": false