The no-network last resort (bundled real dump) now shows a tappable banner
above the tabs — 'Offline data from 15 Aug / Pull to refresh to update
prices' — so stale snapshot data is never presented as live. Banner date
comes from the dump's own data_updated stamp (FuelStore.offlineDataLabel,
ISO 8601 with/without fractional seconds). Cleared on any successful fetch.
- BundledDumpProvider.dataUpdatedStamp (JSONSerialization, app target)
- ContentView: offlineDataDate state, offlineBanner view (tip-card styling,
orange wifi.slash + arrow.clockwise, tap = force refresh), refresh()
clears/sets it, -forceOfflineDump QA launch hook (serves the dump and
skips auto-refresh so the banner stays up for captures)
- Localizable.strings: 3 keys (banner title/subtitle/a11y)
- +3 tests: OfflineDataLabelTests (101 total)