Discovered builds were inserted positionally behind the whitelist entry they
anchored to, so an OTA-installed 02.08.01.53 listed below 02.08.01.52. The list
is now built by appending and sorting once, which also drops the per-entry
insertion scans.
"(installed)" tested whether the library was present on disk, so it marked every
version ever selected - switching leaves the previous library in place. The flag
is now is_loaded, resolved against the plug-in actually loaded, and the two
combo populators share one label helper.
Trim the version whitelist to the latest series plus the pinned legacy build,
and reject out-of-series configured versions at startup, compatibility check,
and load failure - falling back to the latest installed build or the clean
re-download flow so the config never keeps pointing at an unsupported build.
