T10b feedback: error views with 404, 403, maintenance and offline, error boundary, drawn results, confirmation card, saving, sync and connection lines, countdown and timer with rolling digits

tasks/ch01-10.md

@@ -364,17 +364,17 @@
 
 ## T10b Feedback · States
 
-- [ ] ErrorView
-- [ ] ErrorBoundary — renders and logs a `Result` error; never catches panics
-- [ ] NotFound / 404 → `feedback::ErrorView`
-- [ ] NoPermission / 403 → `feedback::ErrorView`
-- [ ] Maintenance → `feedback::ErrorView`
-- [ ] Offline → `feedback::ErrorView`
+- [x] ErrorView → `feedback::ErrorView`
+- [x] ErrorBoundary — renders and logs a `Result` error; never catches panics → `feedback::ErrorBoundary`
+- [x] NotFound / 404 → `feedback::ErrorView::not_found`
+- [x] NoPermission / 403 → `feedback::ErrorView::no_permission`
+- [x] Maintenance → `feedback::ErrorView::maintenance`
+- [x] Offline → `feedback::ErrorView::offline`
 - [x] EmptyState → `feedback::EmptyState`, built with T10a
-- [ ] Result
-- [ ] ConfirmationCard
-- [ ] SavingIndicator
-- [ ] SyncStatus
-- [ ] ConnectionStatus
-- [ ] Countdown
-- [ ] Timer
+- [x] Result → `feedback::ResultView`; a plain `Result` would shadow std's
+- [x] ConfirmationCard → `feedback::ConfirmationCard`
+- [x] SavingIndicator → `feedback::SavingIndicator`
+- [x] SyncStatus → `feedback::SyncStatus`
+- [x] ConnectionStatus → `feedback::ConnectionStatus`; its dot is `shell::OfflineIndicator`'s
+- [x] Countdown → `feedback::Countdown`
+- [x] Timer → `feedback::Timer`