* Note: Track saved nftables configuration changes with Apache-style config/apply timestamp flags, expose the standard restart.cgi header action for themes, and use it as the single apply endpoint. The button expands to “Apply Changes” when saved rules need applying, while the existing Apply Configuration action now routes through restart.cgi and clears the pending state after a successful apply.
Rework the nftables module so Webmin manages its saved nftables configuration as the source of truth instead of directly editing the live ruleset. Add an active ruleset view for inspecting live tables and importing copies into Webmin-managed config if needed, track managed and imported tables with metadata, and prevent externally managed tables from being overwritten during apply.
Co-authored-by: Copilot <copilot@github.com>
