feat(abgen): local-ab follow-ups — reconversion mirroring, production fallback, orphan hardening

Explorer/Assets/DCL/Infrastructure/ECS/Unity/StreamableLoading/AssetBundles/AbgenConversionMetrics.cs

@@ -49,6 +49,9 @@ public enum WarmUpStage
 
         private bool panelOpenRequested;
 
+        private bool contentEditSignaled;
+        private string? contentEditSrc;
+
         private WarmUpStage warmUpStage;
         private string? warmUpSceneId;
         private float warmUpElapsedSeconds;
@@ -280,6 +283,36 @@ public bool TryConsumePanelOpenRequest()
             }
         }
 
+        /// <summary>
+        ///     Signals that the LSD preview server reported a content edit, so the scene's bundles are about
+        ///     to be reconverted. <paramref name="changedSrc" /> names the edited model when the message
+        ///     carried one (UpdateModel); null for whole-scene updates. Rapid successive edits keep the
+        ///     latest name — one reconversion pass covers them all.
+        /// </summary>
+        public void OnContentEdit(string? changedSrc)
+        {
+            lock (gate)
+            {
+                contentEditSignaled = true;
+
+                // Protobuf strings default to "" — treat that as an unnamed (whole-scene) edit.
+                contentEditSrc = string.IsNullOrEmpty(changedSrc) ? null : changedSrc;
+            }
+        }
+
+        /// <summary>True once per <see cref="OnContentEdit" /> burst — consuming it resets the signal.</summary>
+        public bool TryConsumeContentEdit(out string? changedSrc)
+        {
+            lock (gate)
+            {
+                bool signaled = contentEditSignaled;
+                changedSrc = contentEditSrc;
+                contentEditSignaled = false;
+                contentEditSrc = null;
+                return signaled;
+            }
+        }
+
         /// <summary>Adds an informational row to the panel without touching the counters.</summary>
         public void OnMilestone(string message)
         {

Explorer/Assets/DCL/Infrastructure/ECS/Unity/StreamableLoading/AssetBundles/AbgenManifestPrewarm.cs

@@ -0,0 +1,55 @@
+#nullable enable
+
+namespace ECS.StreamableLoading.AssetBundles
+{
+    /// <summary>
+    ///     Hand-off of the abgen sidecar's already-fetched scene manifest to the scene loading lane.
+    ///     Boot holds on the warm-up's manifest request and the reconversion watcher re-fetches it after
+    ///     every content edit, so when the scene lane asks for the same URL the response is already in
+    ///     hand — reusing it removes the server's content revalidation (seconds on a large scene) from
+    ///     the scene-entry critical path. Single entry: local scene development serves exactly one scene.
+    /// </summary>
+    public static class AbgenManifestPrewarm
+    {
+        private static readonly object GATE = new ();
+
+        private static string? url;
+        private static string? json;
+
+        /// <summary>Stores the manifest response fetched from <paramref name="manifestUrl" />, replacing any previous entry.</summary>
+        public static void Set(string manifestUrl, string manifestJson)
+        {
+            lock (GATE)
+            {
+                url = manifestUrl;
+                json = manifestJson;
+            }
+        }
+
+        /// <summary>Drops the stored manifest. Called on a preview content edit, which may change the file census.</summary>
+        public static void Invalidate()
+        {
+            lock (GATE)
+            {
+                url = null;
+                json = null;
+            }
+        }
+
+        /// <summary>True when a manifest fetched from exactly <paramref name="manifestUrl" /> is held; the entry stays for scene reloads.</summary>
+        public static bool TryGet(string manifestUrl, out string manifestJson)
+        {
+            lock (GATE)
+            {
+                if (url == manifestUrl && json != null)
+                {
+                    manifestJson = json;
+                    return true;
+                }
+
+                manifestJson = string.Empty;
+                return false;
+            }
+        }
+    }
+}

Explorer/Assets/DCL/Infrastructure/ECS/Unity/StreamableLoading/AssetBundles/LoadAssetBundleManifestSystem.cs

@@ -59,8 +59,21 @@ private async UniTask<SceneAssetBundleManifest> LoadAssetBundleManifestAsync(str
                       .AppendPath(URLPath.FromString($"{hash}{PlatformUtils.GetCurrentPlatform()}.json"));
 
             URLAddress url = urlBuilder.Build();
-            SceneAbDto sceneAbDto = await webRequestController.GetAsync(new CommonArguments(url, RetryPolicy.WithRetries(1)), ct, reportCategory)
-                                                              .CreateFromJson<SceneAbDto>(WRJsonParser.Newtonsoft, WRThreadFlags.SwitchBackToMainThread);
+
+            // In local-ab the abgen sidecar already fetched this exact manifest — boot holds on the
+            // warm-up's request, and the reconversion watcher re-fetches after every content edit — so
+            // reuse the held response instead of paying the server's content revalidation a second time
+            // on the scene-entry critical path. Empty outside that flow.
+            SceneAbDto sceneAbDto;
+
+            if (AbgenManifestPrewarm.TryGet(url.Value, out string prewarmedJson))
+            {
+                sceneAbDto = JsonUtility.FromJson<SceneAbDto>(prewarmedJson);
+                ReportHub.Log(ReportCategory.ASSET_BUNDLES, $"manifest for {hash} served from the abgen warm-up hand-off (no re-fetch)");
+            }
+            else
+                sceneAbDto = await webRequestController.GetAsync(new CommonArguments(url, RetryPolicy.WithRetries(1)), ct, reportCategory)
+                                                       .CreateFromJson<SceneAbDto>(WRJsonParser.Newtonsoft, WRThreadFlags.SwitchBackToMainThread);
 
             CheckSceneAbDTO(sceneAbDto.Version, hash);