Introduce ChargeMachineDbContext (SQLite) with ArticleContent and
ChargeHistory entities, plus migrations, and wire it up via
ConfigurePluginServices/OnAppInitialize with startup migration and
article-content seeding.
- ChargeEaChargeHandler now records each charge to ChargeHistory
- GetConfigEaChargeHandler serves article config from the DB instead
of hardcoded values, and adds multibills/readagreement fields
- GetLastLogEaChargeHandler returns real daily totals and recent
charge items from history, keyed by session card
- Add GetRecentChargeEaChargeHandler (paginated charge history) and
OpChPassEaChargeHandler (PIN change)
- Update handlers to the new HandleAsync/primary-constructor style,
file-scoped namespaces
- Bump EF Core/Identity packages and Abstractions reference to
net10.0/10.0.10
