feat(toast): action-confirmation toasts with undo & change-list

[ElMagnea]

Visuals

Marking something as watched by mistake

Accidentally removing an item from a watchlist

When adding an item to your watchlist, you can pick another list right after (if need be)

What

Adds a global action-confirmation toast engine, gated behind a new ActionConfirmations preview flag (off by default; on for directors). The shared media mutation hooks fire a confirmation toast after each action, with an inline undo / "change list" affordance.

Action	Toast	Affordance
Add to watchlist	"Title was added to your watchlist"	Change list → opens the manage-lists drawer
Remove from watchlist / favorites / history	"Title was removed…"	Undo
Rate / remove rating	"You rated Title X/10" / "Rating removed"	Undo

How

• New feature module lib/features/action-toast/ — a module-store singleton (mirrors useDismissals / markAsWatchedDrawerStore) + ActionToastHost mounted once in the layout, reusing the existing Snackbar primitive.
• Undo runs the sibling hook method (via executeOrEnqueue), not the raw *Request — so it stays offline-aware, cache-invalidating, and consistent with the optimistic read overlay.
• Global manage-lists drawer opener (manageListsDrawerStore + provider) so "change list" can open the drawer from anywhere.
• Snackbar polish (shared): bold inline title (MessageWithBold), a theme-aware outline "pill" action (stroke token added to both modes.scss mixins), a hairline border, and a bottom fly-in/out animation (|global; respects prefers-reduced-motion).

Notes / scope

• Behind a flag → safe to merge; no behavior change until toggled on.
• Verified in both light and dark themes.
• Deferred (follow-ups): useRemoveFromHistory (row-level, lossy undo) not wired; ratings "Change" (needs a global rating drawer); the outline-button look is scoped to the toast — a global button restyle is its own pass.

Verification

deno fmt ✓ · svelte-check 0/0 ✓ · vitest 2418 passed ✓ · i18n:check ✓. Undo is covered by tests that assert the real reverse request fires (watchlist / favorites / history).

🤖 Generated with Claude Code

[michaldrabik]

• for actions that already have a confirmation dialog "Are you sure..." adding this seems a bit excessive and just noise?
• for Rating Prompt UI can we do this somehow so it does not make everything taller and break symmetry? :P Maybe just an undo icon button next to X is enough, should be clear.
• also just thinking now that Rating Prompt is not something strictly related to your active action of marking as watched so that might not be the best place to undo anything (might have scrobbled, checkin might have ended, other client might have marked etc.). 🤔

[deepsource-io]

DeepSource Code Review

We reviewed changes in c78500c...50f6171 on this pull request. Below is the summary for the review, and you can see the individual issues we found as inline review comments.

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PR Report Card

Overall Grade

Security   Reliability   Complexity   Hygiene   Coverage

Code Review Summary

Analyzer	Status	Updated (UTC)	Details
JavaScript		Aug 14, 2026 3:43p.m.	Review ↗
Code coverage		Aug 14, 2026 3:43p.m.	Review ↗

Code Coverage Summary

Language	Line Coverage (Overall)
Aggregate	68.2% [▼ down 0.1% from main]
Javascript	68.2% [▼ down 0.1% from main]

➟ Additional coverage metrics may have been reported. See full coverage report ↗

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