srcds_run is a shell script that cd's to its own dirname before exec'ing
srcds_linux, so WorkingDirectory has no effect — the binary's path is what
determines where the engine reads gameinfo.txt and addons from. Pointing
at installation/srcds_run resolved everything against the lower layer, so
overlay-provided Metamod/SourceMod plugins and cfgs (zonemod, confogl)
never loaded. Switch to runtime/%i/merged/srcds_run so the engine sees
the merged tree.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>