Resume-prompt Option C — first in-engine consumer of
`ToastVariant::Error`. The variant has had a slot in the enum
since v0.20.0's toast system landed; this commit wires a real
driver event so the slot is no longer dead code.
### Driver: MoveRejectedEvent
When a player tries an illegal placement (drops dragged cards on
a real pile but the move violates the rules), `MoveRejectedEvent`
fires. The existing rejection-feedback chain plays
`card_invalid.wav` (audio cue) and triggers the destination-pile
shake (visual cue via `feedback_anim_plugin`). This commit adds a
third leg — a 2-second pink-bordered Error toast reading
"Invalid move" — primarily for accessibility:
- **Audio cue alone** doesn't help deaf players.
- **Visual shake alone** is brief and easy to miss for low-vision
players or anyone with reduce-motion enabled (which gates the
shake's animation timing).
- **Toast text** is persistent ~2 s, readable, and unambiguous.
The three legs together cover the major perception channels.
### Implementation
New `handle_move_rejected_toast` system in `animation_plugin`
mirrors the shape of `handle_xp_awarded_toast` — read events,
fire `spawn_toast(commands, "Invalid move", 2.0,
ToastVariant::Error)`. Registered in the plugin's Update set
between `handle_xp_awarded_toast` and `tick_toasts` so the toast
spawn pipeline picks it up the same frame the event fires.
`AnimationPlugin::build` gains
`.add_message::<MoveRejectedEvent>()` so the message is
initialized when the plugin runs under MinimalPlugins (tests).
The message is also registered by `feedback_anim_plugin` —
Bevy's `add_message` is idempotent, so both registrations
coexist cleanly.
Also drops the `#[allow(dead_code)]` from `ToastVariant::Error`
(stale now that the variant has a real consumer) and updates the
variant's doc comment to point at `handle_move_rejected_toast`.
### Test
New `move_rejected_event_spawns_error_toast` pins the wiring:
firing a `MoveRejectedEvent` spawns exactly one `ToastOverlay`
on the next tick. Matches the shape of the existing
`info_toast_event_spawns_toast_overlay` test. 1195 passing
(+1 from prior 1194).
Workspace clippy clean.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
funman300
68d50b5021