If wg0.conf exists but is empty or has no [Interface] section,
apply_config previously found no lines to update and silently
returned with no changes — leaving the container broken on next
restart with an empty config.
Fix: detect empty/missing [Interface] section and regenerate the
full config from generate_config() before applying field updates.
This was the root cause of port changes not propagating:
apply_config was called but found nothing to patch in an empty file.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
roof
729c401c33