Add a 'Re-sync now' button to the Proxmox auto-sync settings section that
triggers an immediate inventory import (POST /proxmox/sync-now) using the
server env config — the manual counterpart to scheduled auto-sync.
Also fix a dual-source-of-truth bug: Proxmox connection config (host, port,
token, verify_tls) is now env-only and never persisted to scan_config.json.
Previously save_overrides() dumped host/port/verify alongside scan settings,
so saving an unrelated setting wrote an empty proxmox_host that load_overrides
then clobbered PROXMOX_HOST with on every boot. Only the auto-sync activation
(sync_enabled + sync_interval) stays user-editable and persisted.
ha-relevant: no
Pouzor
9437a74147