The base URL handed to PXE clients was built as `http://{ip}` with no
port, ignoring OPENPXE_HTTP_PORT. Every client-facing URL derives from
it — the DHCP-proxy iPXE filename, UEFI HTTP boot, and the boot menu's
kernel/initrd/ISO links — so any non-80 deployment told clients to fetch
:80 (the wrong service). On Unraid that's the webGUI, which 301s to
https; iPXE (no TLS) then fails the chain with "Operation not supported".
This broke the exact configuration the Unraid template recommends
(HTTP port 4200, to avoid the webGUI on :80).
Fix: build_public_base_url(ip, port) includes the port unless it's 80,
so http://10.0.0.5 stays clean while http://10.0.0.5:4200 is reachable.
One source of truth, so the whole URL surface is corrected at once.
Regression-tested (port included for 4200/8080, omitted for 80).
Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>
