reconcileFromFilesystem() skipped every ZIM whose filename starts with
`wikipedia_en_`, on the assumption that all such files are managed by the
WikipediaSelection model. But curated category tiers ship Wikipedia-themed
ZIMs (e.g. Medicine → Comprehensive includes `wikipedia_en_medicine_maxi`),
so those files were skipped during reconcile and their InstalledResource
rows got wiped on every restart — silently downgrading the detected tier.
Skip only the single file actually tracked by WikipediaSelection, matched
by exact filename instead of the `wikipedia_en_` prefix.
Reimplemented in-house from @johno10661's PR #774 (which was trapped on a
stale base); credit to them for the diagnosis and fix.
Closes#774
df47139846