fix(cache): expire cached version-tag manifests after 24h, not 60d

rpardini/docker-registry-proxy keeps manifests of tags matching its
secondary regex (three digit groups, e.g. yourls:1.10.6-apache) for
MANIFEST_CACHE_SECONDARY_TIME, 60d by default. An upstream re-push of
such a tag stays invisible for two months: the cache still serves
yourls:1.10.6-apache with PHP 8.5.11 while upstream ships 8.5.12.

Set it to 24h. The primary tier (10m) and the default (1h) are shorter
already and stay as they are. The entrypoint writes the value into
proxy_cache_valid, so it applies once infinito-registry-cache is
recreated; manifests cached before keep their old expiry until purged.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

compose/cache.override.yml

@@ -8,6 +8,7 @@ services:
     container_name: infinito-registry-cache
     environment:
       ENABLE_MANIFEST_CACHE: "true"
+      MANIFEST_CACHE_SECONDARY_TIME: "24h"
       AUTH_REGISTRIES: ""
       CACHE_MAX_SIZE: "${INFINITO_CACHE_REGISTRY_MAX_SIZE:?Run 'make dotenv' to generate the .env single source of truth}"
       DISABLE_IPV6: "true"