fix(chat): make cached media load on safari

src/data/repositories/chat_media_cache_coordinator.ts

@@ -109,10 +109,13 @@ export class ChatMediaCacheCoordinator {
       );
     }
 
-    const blob = await response.blob();
-    if (blob.size <= 0) {
-      throw new Error("Media download returned an empty blob.");
+    const bytes = await response.arrayBuffer();
+    if (bytes.byteLength <= 0) {
+      throw new Error("Media download returned empty bytes.");
     }
+    const mimeType =
+      response.headers.get("content-type") ||
+      fallbackChatMediaMimeType(input.kind);
 
     const saveResult = await this.mediaStorage.saveMedia({
       cacheKey,
@@ -120,11 +123,8 @@ export class ChatMediaCacheCoordinator {
       messageId: input.messageId,
       kind: input.kind,
       remoteUrl: input.remoteUrl,
-      blob,
-      mimeType:
-        blob.type ||
-        response.headers.get("content-type") ||
-        fallbackChatMediaMimeType(input.kind),
+      bytes,
+      mimeType,
     });
     if (Result.isErr(saveResult)) throw saveResult.error;
     void requestBrowserPersistentStorageOnce();

src/data/repositories/interfaces/ichat_repository.ts

@@ -69,12 +69,12 @@ export interface IChatRepository {
   /** 获取本地消息数量。 */
   getLocalMessageCount(): Promise<Result<number>>;
 
-  /** 获取本地缓存的图片 / 音频 Blob。 */
+  /** 获取本地缓存的图片 / 音频。 */
   getCachedMedia(
     input: ChatMediaLookupInput,
   ): Promise<Result<LocalChatMediaRow | null>>;
 
-  /** 下载并缓存远程图片 / 音频 Blob。 */
+  /** 下载并缓存远程图片 / 音频。 */
   cacheRemoteMedia(
     input: CacheRemoteChatMediaInput,
   ): Promise<Result<LocalChatMediaRow>>;

src/data/storage/chat/local_chat_db.ts

@@ -39,7 +39,10 @@ export interface LocalChatMediaRow {
   messageId: string;
   kind: ChatMediaKind;
   remoteUrl: string;
-  blob: Blob;
+  /** v3+ stores raw bytes instead of Blob to avoid iOS WebKit Blob URL issues. */
+  bytes?: ArrayBuffer;
+  /** Legacy v2 field. Read-only fallback for users who already have cached media. */
+  blob?: Blob;
   mimeType: string;
   byteSize: number;
   createdAt: number;

src/data/storage/chat/local_chat_media_storage.ts

@@ -16,7 +16,7 @@ export interface SaveLocalChatMediaInput {
   messageId: string;
   kind: ChatMediaKind;
   remoteUrl: string;
-  blob: Blob;
+  bytes: ArrayBuffer;
   mimeType: string;
 }
 
@@ -44,9 +44,9 @@ export class LocalChatMediaStorage {
     try {
       const row = (await this.db.media.get(cacheKey)) ?? null;
       if (row) {
-        await this.db.media.update(cacheKey, {
-          lastAccessedAt: Date.now(),
-        });
+        const normalizedRow = await this.normalizeLegacyMediaRow(row);
+        await this.db.media.update(cacheKey, { lastAccessedAt: Date.now() });
+        return Result.ok(normalizedRow);
       }
       return Result.ok(row);
     } catch (e) {
@@ -64,9 +64,9 @@ export class LocalChatMediaStorage {
         messageId: input.messageId,
         kind: input.kind,
         remoteUrl: input.remoteUrl,
-        blob: input.blob,
+        bytes: input.bytes,
         mimeType: input.mimeType,
-        byteSize: input.blob.size,
+        byteSize: input.bytes.byteLength,
         createdAt: existing?.createdAt ?? now,
         updatedAt: now,
         lastAccessedAt: now,
@@ -85,4 +85,35 @@ export class LocalChatMediaStorage {
       return Result.err(e);
     }
   }
+
+  private async normalizeLegacyMediaRow(
+    row: LocalChatMediaRow,
+  ): Promise<LocalChatMediaRow> {
+    if (row.bytes && row.bytes.byteLength > 0) return row;
+    if (!row.blob || row.blob.size <= 0) return row;
+
+    const bytes = await row.blob.arrayBuffer();
+    const now = Date.now();
+    const normalizedRow: LocalChatMediaRow = {
+      cacheKey: row.cacheKey,
+      ownerKey: row.ownerKey,
+      messageId: row.messageId,
+      kind: row.kind,
+      remoteUrl: row.remoteUrl,
+      bytes,
+      mimeType:
+        row.mimeType || row.blob.type || fallbackMediaMimeType(row.kind),
+      byteSize: bytes.byteLength,
+      createdAt: row.createdAt,
+      updatedAt: now,
+      lastAccessedAt: now,
+    };
+
+    await this.db.media.put(normalizedRow);
+    return normalizedRow;
+  }
+}
+
+function fallbackMediaMimeType(kind: ChatMediaKind): string {
+  return kind === "image" ? "image/*" : "audio/mpeg";
 }