fix(ui): reconcile active operations from local scans

Local operation spinners were driven by begin, finish, and failure event
history. If one of those lifecycle events was missed, the Tauri bridge could
keep a stale active operation and the React state would keep showing an
in-progress spinner until restart.

Peer local scan updates now carry an authoritative active-operation snapshot.
The peer still suppresses active game roots from peer-facing library deltas,
but it emits LocalGamesUpdated to the UI even when no library delta changed so
the snapshot can clear stale state after rollback or completion. The Tauri
bridge replaces its active-operation map from that snapshot, emits it with the
games-list payload, and the React merge uses it to restore download, install,
update, and uninstall spinners from current peer state rather than event
history alone.

This also enables the Tauri lib unit-test target so the reconciliation helper
can stay covered by the workspace test recipe.

Test Plan:
- git diff --check
- just fmt
- just clippy
- just test

Follow-up-Plan: FOLLOW_UP_2.md

crates/lanspread-tauri-deno-ts/src-tauri/src/lib.rs

@@ -17,6 +17,8 @@ use lanspread_db::db::{
     GameFileDescription,
 };
 use lanspread_peer::{
+    ActiveOperation,
+    ActiveOperationKind,
     InstallOperation,
     PeerCommand,
     PeerEvent,
@@ -49,7 +51,7 @@ struct LanSpreadState {
 
 struct PeerEventTx(UnboundedSender<PeerEvent>);
 
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, serde::Serialize)]
 enum UiOperationKind {
     Downloading,
     Installing,
@@ -57,6 +59,18 @@ enum UiOperationKind {
     Uninstalling,
 }
 
+#[derive(Clone, Debug, PartialEq, Eq, serde::Serialize)]
+struct UiActiveOperation {
+    id: String,
+    operation: UiOperationKind,
+}
+
+#[derive(Clone, Debug, serde::Serialize)]
+struct GamesListPayload {
+    games: Vec<Game>,
+    active_operations: Vec<UiActiveOperation>,
+}
+
 struct SidecarUnpacker {
     app_handle: AppHandle,
 }
@@ -527,13 +541,59 @@ async fn refresh_games_list(app_handle: &AppHandle) {
 
     drop(game_db);
 
-    if let Err(e) = app_handle.emit("games-list-updated", Some(games_to_emit)) {
+    let active_operations = {
+        let active_operations = state.active_operations.read().await;
+        ui_active_operations_from_map(&active_operations)
+    };
+
+    let payload = GamesListPayload {
+        games: games_to_emit,
+        active_operations,
+    };
+
+    if let Err(e) = app_handle.emit("games-list-updated", Some(payload)) {
         log::error!("Failed to emit games-list-updated event: {e}");
     } else {
         log::info!("Emitted games-list-updated event");
     }
 }
 
+fn ui_active_operations_from_map(
+    active_operations: &HashMap<String, UiOperationKind>,
+) -> Vec<UiActiveOperation> {
+    let mut snapshot = active_operations
+        .iter()
+        .map(|(id, operation)| UiActiveOperation {
+            id: id.clone(),
+            operation: *operation,
+        })
+        .collect::<Vec<_>>();
+    snapshot.sort_by(|left, right| left.id.cmp(&right.id));
+    snapshot
+}
+
+fn reconcile_active_operations(
+    active_operations: &mut HashMap<String, UiOperationKind>,
+    snapshot: &[ActiveOperation],
+) {
+    active_operations.clear();
+    active_operations.extend(snapshot.iter().map(|operation| {
+        (
+            operation.id.clone(),
+            ui_operation_from_peer(operation.operation),
+        )
+    }));
+}
+
+fn ui_operation_from_peer(operation: ActiveOperationKind) -> UiOperationKind {
+    match operation {
+        ActiveOperationKind::Downloading => UiOperationKind::Downloading,
+        ActiveOperationKind::Installing => UiOperationKind::Installing,
+        ActiveOperationKind::Updating => UiOperationKind::Updating,
+        ActiveOperationKind::Uninstalling => UiOperationKind::Uninstalling,
+    }
+}
+
 #[tauri::command]
 async fn update_game_directory(app_handle: tauri::AppHandle, path: String) -> tauri::Result<()> {
     log::info!("update_game_directory: {path}");
@@ -816,8 +876,16 @@ async fn handle_peer_event(app_handle: &AppHandle, event: PeerEvent) {
             log::info!("PeerEvent::ListGames received");
             update_game_db(games, app_handle.clone()).await;
         }
-        PeerEvent::LocalGamesUpdated(local_games) => {
+        PeerEvent::LocalGamesUpdated {
+            games: local_games,
+            active_operations,
+        } => {
             log::info!("PeerEvent::LocalGamesUpdated received");
+            {
+                let state = app_handle.state::<LanSpreadState>();
+                let mut ui_active_operations = state.active_operations.write().await;
+                reconcile_active_operations(&mut ui_active_operations, &active_operations);
+            }
             update_local_games_in_db(local_games, app_handle.clone()).await;
         }
         PeerEvent::GotGameFiles {
@@ -1061,6 +1129,69 @@ async fn handle_download_finished(app_handle: &AppHandle, id: String) {
         .remove(&id);
 }
 
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn active_operation_reconciliation_replaces_stale_ui_history() {
+        let mut active_operations = HashMap::from([
+            ("stale".to_string(), UiOperationKind::Installing),
+            ("keep".to_string(), UiOperationKind::Downloading),
+        ]);
+        let snapshot = vec![
+            ActiveOperation {
+                id: "keep".to_string(),
+                operation: ActiveOperationKind::Updating,
+            },
+            ActiveOperation {
+                id: "new".to_string(),
+                operation: ActiveOperationKind::Uninstalling,
+            },
+        ];
+
+        reconcile_active_operations(&mut active_operations, &snapshot);
+
+        assert_eq!(active_operations.len(), 2);
+        assert_eq!(
+            active_operations.get("keep"),
+            Some(&UiOperationKind::Updating)
+        );
+        assert_eq!(
+            active_operations.get("new"),
+            Some(&UiOperationKind::Uninstalling)
+        );
+        assert!(
+            !active_operations.contains_key("stale"),
+            "snapshot reconciliation should drop stale UI operations"
+        );
+    }
+
+    #[test]
+    fn active_operation_payload_is_sorted_for_stable_ui_updates() {
+        let active_operations = HashMap::from([
+            ("zeta".to_string(), UiOperationKind::Downloading),
+            ("alpha".to_string(), UiOperationKind::Installing),
+        ]);
+
+        let snapshot = ui_active_operations_from_map(&active_operations);
+
+        assert_eq!(
+            snapshot,
+            vec![
+                UiActiveOperation {
+                    id: "alpha".to_string(),
+                    operation: UiOperationKind::Installing,
+                },
+                UiActiveOperation {
+                    id: "zeta".to_string(),
+                    operation: UiOperationKind::Downloading,
+                },
+            ]
+        );
+    }
+}
+
 #[allow(clippy::missing_panics_doc)]
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {