fix: serialize database activity during playout

Web/app.js

@@ -173,7 +173,7 @@
       error: null,
       lastSignature: ""
     },
-    database: { sources: [], loading: true, lastSignature: "" },
+    database: { sources: [], loading: true, lastSignature: "", latestSequence: 0 },
     liveData: {
       requestId: null,
       view: null,
@@ -1400,6 +1400,12 @@
   }
 
   function handleDatabaseStatus(payload) {
+    const sequence = payload?.sequence;
+    if (!playoutSafety.isNewerDatabaseStatusSequence(
+        state.database.latestSequence,
+        sequence)) return;
+
+    state.database.latestSequence = sequence;
     state.database.sources = normalizedDatabaseSources(payload?.sources);
     state.database.loading = false;
     renderDatabaseStatus();

Web/playout-safety.js

@@ -69,6 +69,14 @@
     return !refreshFaulted && error?.isRefreshFault === true;
   }
 
+  function isNewerDatabaseStatusSequence(latestSequence, incomingSequence) {
+    const latest = Number.isSafeInteger(latestSequence) && latestSequence >= 0
+      ? latestSequence
+      : 0;
+    return Number.isSafeInteger(incomingSequence) &&
+      incomingSequence > 0 && incomingSequence > latest;
+  }
+
   function resolveStoredCatalogIndex(catalog, builderKey, cutCode) {
     if (!Array.isArray(catalog)) return -1;
     const exact = catalog.findIndex(item =>
@@ -90,6 +98,7 @@
     canClearCommandError,
     playlistSnapshotLocked,
     shouldClearRefreshError,
+    isNewerDatabaseStatusSequence,
     resolveStoredCatalogIndex
   };
 });