fix: Bug - Sending files and attachment issues

Hydrate playable media after disk receive, relay file-announce to sibling
devices via account_sync, bind DM attachments to pre-allocated message ids,
and improve gallery retry/cancel UX with bounded parallel auto-downloads.

Co-authored-by: Cursor <cursoragent@cursor.com>

toju-app/src/app/domains/attachment/application/services/attachment-transfer.service.ts

@@ -229,6 +229,10 @@ export class AttachmentTransferService {
   }
 
   requestImageFromAnyPeer(messageId: string, attachment: Attachment): Promise<void> {
+    if ((attachment.receivedBytes ?? 0) > 0 || this.hasPendingRequest(messageId, attachment.id)) {
+      this.cancelRequest(messageId, attachment);
+    }
+
     return this.requestFromAnyPeer(messageId, attachment);
   }
 
@@ -456,22 +460,22 @@ export class AttachmentTransferService {
   }
 
   cancelRequest(messageId: string, attachment: Attachment): void {
-    const targetPeerId = attachment.uploaderPeerId;
-
-    if (!targetPeerId)
-      return;
-
     try {
+      const requestKey = this.buildRequestKey(messageId, attachment.id);
       const assemblyKey = `${messageId}:${attachment.id}`;
+      const pendingPeers = this.runtimeStore.getPendingRequestPeers(requestKey);
 
       this.runtimeStore.deleteChunkBuffer(assemblyKey);
       this.runtimeStore.deleteChunkCount(assemblyKey);
+      this.runtimeStore.deletePendingRequest(requestKey);
       void this.deleteDiskReceiveAssembly(assemblyKey);
+      this.chunkAcks.cancelPendingForFile(messageId, attachment.id);
 
       attachment.receivedBytes = 0;
       attachment.speedBps = 0;
       attachment.startedAtMs = undefined;
       attachment.lastUpdateMs = undefined;
+      attachment.requestError = undefined;
 
       if (attachment.objectUrl) {
         try {
@@ -489,8 +493,21 @@ export class AttachmentTransferService {
         messageId,
         fileId: attachment.id
       };
+      const peersToNotify = new Set<string>();
 
-      this.webrtc.sendToPeer(targetPeerId, fileCancelEvent);
+      if (pendingPeers) {
+        for (const peerId of pendingPeers) {
+          peersToNotify.add(peerId);
+        }
+      }
+
+      if (attachment.uploaderPeerId) {
+        peersToNotify.add(attachment.uploaderPeerId);
+      }
+
+      for (const peerId of peersToNotify) {
+        this.webrtc.sendToPeer(peerId, fileCancelEvent);
+      }
     } catch { /* best-effort */ }
   }
 
@@ -997,6 +1014,23 @@ export class AttachmentTransferService {
     this.runtimeStore.touch();
     void this.persistence.persistAttachmentMeta(attachment);
     void this.announceLocalHost(attachment);
+    void this.hydratePlayableMediaAfterDiskReceive(attachment);
+  }
+
+  private async hydratePlayableMediaAfterDiskReceive(attachment: Attachment): Promise<void> {
+    if (!this.isPlayableMedia(attachment) || !attachment.savedPath) {
+      return;
+    }
+
+    const nativeUrl = await this.attachmentStorage.getFileUrl(attachment.savedPath);
+
+    if (nativeUrl) {
+      attachment.objectUrl = nativeUrl;
+      this.runtimeStore.touch();
+      return;
+    }
+
+    await this.persistence.ensureInlineDisplayObjectUrl(attachment);
   }
 
   private async getOrCreateDiskReceiveAssembly(