SubscriptionService held one provider per backend and each resolved its
instance from settingsManager.subscriptionAccount, falling back to "the
first enabled Invidious instance" when that was unset. With several logins
possible on one instance that model breaks twice: two accounts would share
a single in-memory subscription cache, and the fallback could send an
account's request to a server it holds no credential for.
Providers are now built per account and cached by account ID, and each
resolves its instance and credential from the account it was built for -
no fallback. The protocol's accountType becomes a DataContext, which is
what actually identifies a provider now.
Views that branched on "is the subscription account local" read the context
instead, and the settings picker writes both stores. Keeping the legacy
setting in step is deliberate for now: several views still read it, and
letting the two diverge would show one account in the UI while serving
another's data. The Phase 3 switcher removes the last readers.
Signing out discards the account's provider so its cached subscriptions
cannot be served after the account is gone.
When an Invidious/Piped account is active, several views read the local
SwiftData subscription store instead of the account, so counts
contradicted each other (Home tile said 10 while the Channels list
showed the server's 2):
- Home Channels tile now uses the provider's count via new
SubscriptionService.cachedSubscriptionCount (fetched once in the
background when the server cache isn't populated yet)
- Export footer and export content use the active account's list;
export runs async with a spinner and surfaces fetch errors as a toast
- CSV/OPML import routes through SubscriptionService.importSubscriptions,
subscribing on the server for server accounts instead of silently
writing to the invisible local store
- ChannelView subscribe-state is corrected via the provider after the
optimistic local-store read; unused *Sync write helpers removed
- Server-account subscribe/unsubscribe/import now post
subscriptionsDidChange so other views refresh
- New "Delete Local Subscription Data" section in Subscriptions
settings (visible with a server account) clears the local store and
queues CloudKit deletions so iCloud doesn't restore it
