A new py/lora_layout_cache.py keeps one (install, layout) entry and reuses it
while the configured path, the plugin settings file's and the settings file's
signatures (st_mtime_ns, st_size), the install and every media root's real
path are unchanged and the entry is younger than 30 s. A load whose watched
file changed within 3 s (git's racy rule), could not be checked, or whose
settings were unreadable serves its request only. clear() bumps a generation
so a load that started earlier stores nothing. Hits take no lock.
Not wired yet; phase 2 puts it behind the image hot paths.
Vito Sansevero
9a03766090