feat(engine): emit SyncCompleteEvent on pull resolve

ARCHITECTURE.md §5 lists SyncCompleteEvent(Result<SyncResponse, String>) as
a cross-system event, but it was never declared or fired. Add the message
to events.rs, register it in SyncPlugin, and emit it from poll_pull_result
on both the success path (carrying the merged payload + conflicts as
SyncResponse) and the failure path (carrying the user-facing error
message). UI/persistence systems can now react to sync completion without
polling SyncStatusResource.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

solitaire_engine/src/events.rs

@@ -4,6 +4,7 @@ use bevy::prelude::Message;
 use solitaire_core::game_state::GameMode;
 use solitaire_core::pile::PileType;
 use solitaire_data::AchievementRecord;
+use solitaire_sync::SyncResponse;
 
 /// Request to move `count` cards from `from` to `to`. Fired by input systems,
 /// consumed by `GamePlugin`.
@@ -78,6 +79,16 @@ pub struct AchievementUnlockedEvent(pub AchievementRecord);
 #[derive(Message, Debug, Clone, Copy, Default)]
 pub struct ManualSyncRequestEvent;
 
+/// Fired by `SyncPlugin` after a pull task resolves and the merged result has
+/// been persisted to disk. `Ok(SyncResponse)` carries the merged payload plus
+/// any `ConflictReport`s the merge produced. `Err(String)` carries a
+/// human-readable failure message (network, auth, serialization, etc.).
+///
+/// UI systems listen for this to refresh views without polling
+/// `SyncStatusResource`. See [ARCHITECTURE.md §4](../../ARCHITECTURE.md).
+#[derive(Message, Debug, Clone)]
+pub struct SyncCompleteEvent(pub Result<SyncResponse, String>);
+
 /// Fired by `InputPlugin` when N is pressed while a game is in progress
 /// but confirmation has not yet been received. The animation plugin shows
 /// a "Press N again to confirm" toast. A second N press within the

solitaire_engine/src/lib.rs

@@ -69,7 +69,7 @@ pub use events::{
     AchievementUnlockedEvent, CardFaceRevealedEvent, CardFlippedEvent, DrawRequestEvent,
     ForfeitEvent, GameWonEvent, HintVisualEvent, InfoToastEvent, ManualSyncRequestEvent,
     MoveRejectedEvent, MoveRequestEvent, NewGameConfirmEvent, NewGameRequestEvent,
-    StateChangedEvent, UndoRequestEvent, XpAwardedEvent,
+    StateChangedEvent, SyncCompleteEvent, UndoRequestEvent, XpAwardedEvent,
 };
 pub use game_plugin::{ConfirmNewGameScreen, GameMutation, GameOverScreen, GamePlugin, GameStatePath};
 pub use help_plugin::{HelpPlugin, HelpScreen};

solitaire_engine/src/sync_plugin.rs

@@ -22,10 +22,10 @@ use solitaire_data::{
     save_achievements_to, save_progress_to, save_stats_to, AchievementRecord, PlayerProgress,
     StatsSnapshot, SyncError, SyncProvider,
 };
-use solitaire_sync::{merge, SyncPayload};
+use solitaire_sync::{merge, SyncPayload, SyncResponse};
 
 use crate::achievement_plugin::{AchievementsResource, AchievementsStoragePath};
-use crate::events::ManualSyncRequestEvent;
+use crate::events::{ManualSyncRequestEvent, SyncCompleteEvent};
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath};
 use crate::resources::{SyncStatus, SyncStatusResource};
 use crate::stats_plugin::{StatsResource, StatsStoragePath};
@@ -94,6 +94,7 @@ impl Plugin for SyncPlugin {
             .init_resource::<PullTaskResult>()
             .init_resource::<PullTask>()
             .add_message::<ManualSyncRequestEvent>()
+            .add_message::<SyncCompleteEvent>()
             .add_systems(Startup, start_pull)
             .add_systems(Update, (poll_pull_result, handle_manual_sync_request))
             .add_systems(Last, push_on_exit);
@@ -161,6 +162,7 @@ fn poll_pull_result(
     achievements_path: Res<AchievementsStoragePath>,
     mut progress: ResMut<ProgressResource>,
     progress_path: Res<ProgressStoragePath>,
+    mut complete_writer: MessageWriter<SyncCompleteEvent>,
 ) {
     let Some(task) = task_res.0.as_mut() else {
         return;
@@ -173,7 +175,7 @@ fn poll_pull_result(
     match result {
         Ok(remote) => {
             let local = build_payload(&stats.0, &achievements.0, &progress.0);
-            let (merged, _conflicts) = merge(&local, &remote);
+            let (merged, conflicts) = merge(&local, &remote);
 
             // Persist merged state atomically.
             if let Some(p) = &stats_path.0
@@ -190,10 +192,17 @@ fn poll_pull_result(
                 }
 
             // Update in-world resources.
-            stats.0 = merged.stats;
+            let now = Utc::now();
-            achievements.0 = merged.achievements;
+            stats.0 = merged.stats.clone();
-            progress.0 = merged.progress;
+            achievements.0 = merged.achievements.clone();
-            status.0 = SyncStatus::LastSynced(Utc::now());
+            progress.0 = merged.progress.clone();
+            status.0 = SyncStatus::LastSynced(now);
+
+            complete_writer.write(SyncCompleteEvent(Ok(SyncResponse {
+                merged,
+                server_time: now,
+                conflicts,
+            })));
         }
         Err(SyncError::UnsupportedPlatform) => {
             // No backend configured — not an error, just leave status as Idle.
@@ -207,7 +216,8 @@ fn poll_pull_result(
                 SyncError::Serialization(_) => format!("Unexpected server response: {e}"),
                 SyncError::UnsupportedPlatform => unreachable!("handled above"),
             };
-            status.0 = SyncStatus::Error(msg);
+            status.0 = SyncStatus::Error(msg.clone());
+            complete_writer.write(SyncCompleteEvent(Err(msg)));
         }
     }
 }