refactor(chat): tighten media cache boundaries

src/app/chat/components/fullscreen-image-viewer.tsx

@@ -14,7 +14,12 @@ import { ChevronLeft } from "lucide-react";
 import Image from "next/image";
 import { useEffect } from "react";
 
-import { useCachedChatMediaUrl } from "../hooks/use-cached-chat-media-url";
+import {
+  isBrowserLocalChatImageSource,
+  normalizeChatImageSource,
+} from "@/lib/chat/chat_media_url";
+import { useCachedChatMediaUrl } from "@/lib/chat/use_cached_chat_media_url";
+
 import styles from "./fullscreen-image-viewer.module.css";
 
 export interface FullscreenImageViewerProps {
@@ -46,13 +51,8 @@ export function FullscreenImageViewer({
     return () => document.removeEventListener("keydown", handleKey);
   }, [onClose]);
 
-  const sourceUrl = mediaUrl || imageUrl;
+  const src = normalizeChatImageSource(mediaUrl || imageUrl);
-  const src = sourceUrl.startsWith("data:") ||
+  const shouldUseNativeImage = isBrowserLocalChatImageSource(src);
-    sourceUrl.startsWith("http") ||
-    sourceUrl.startsWith("blob:")
-    ? sourceUrl
-    : `data:image/png;base64,${sourceUrl}`;
-  const shouldUseNativeImage = isBrowserLocalImageSrc(src);
 
   if (imagePaywalled) {
     return (
@@ -131,7 +131,3 @@ export function FullscreenImageViewer({
     </div>
   );
 }
-
-function isBrowserLocalImageSrc(src: string): boolean {
-  return src.startsWith("blob:") || src.startsWith("data:");
-}

src/app/chat/components/image-bubble.tsx

@@ -13,8 +13,12 @@ import { useRouter } from "next/navigation";
 import { useState } from "react";
 
 import { ROUTE_BUILDERS } from "@/router/routes";
+import {
+  isBrowserLocalChatImageSource,
+  normalizeChatImageSource,
+} from "@/lib/chat/chat_media_url";
+import { useCachedChatMediaUrl } from "@/lib/chat/use_cached_chat_media_url";
 
-import { useCachedChatMediaUrl } from "../hooks/use-cached-chat-media-url";
 import styles from "./image-bubble.module.css";
 
 export interface ImageBubbleProps {
@@ -36,9 +40,9 @@ export function ImageBubble({
     kind: "image",
   });
 
-  const src = decodeBase64Image(mediaUrl || imageUrl);
+  const src = normalizeChatImageSource(mediaUrl || imageUrl);
   const canOpen = Boolean(messageId);
-  const shouldUseNativeImage = isBrowserLocalImageSrc(src);
+  const shouldUseNativeImage = isBrowserLocalChatImageSource(src);
 
   const openImage = () => {
     if (!messageId) return;
@@ -85,17 +89,3 @@ export function ImageBubble({
     </div>
   );
 }
-
-/** 解析 base64 data URI（`data:image/png;base64,...`），否则原样返回 */
-function decodeBase64Image(uri: string): string {
-  // 已是 data URI 或 http(s) URL：直接返回
-  if (uri.startsWith("data:") || uri.startsWith("http")) {
-    return uri;
-  }
-  // 裸 base64 字符串 → 包装成 data URI（PNG 兜底）
-  return `data:image/png;base64,${uri}`;
-}
-
-function isBrowserLocalImageSrc(src: string): boolean {
-  return src.startsWith("blob:") || src.startsWith("data:");
-}

src/app/chat/components/voice-bubble.tsx

@@ -3,7 +3,7 @@
 import { LockKeyhole, Pause, Play } from "lucide-react";
 import { useEffect, useRef, useState } from "react";
 
-import { useCachedChatMediaUrl } from "../hooks/use-cached-chat-media-url";
+import { useCachedChatMediaUrl } from "@/lib/chat/use_cached_chat_media_url";
 import styles from "./voice-bubble.module.css";
 
 export interface VoiceBubbleProps {

src/data/dto/chat/chat_media.ts

@@ -0,0 +1 @@
+export type ChatMediaKind = "image" | "audio";

src/data/dto/chat/index.ts

@@ -4,6 +4,7 @@
 
 export * from "./chat_history_response";
 export * from "./chat_list_item";
+export * from "./chat_media";
 export * from "./chat_message";
 export * from "./chat_send_response";
 export * from "./chat_sync_data";

src/data/repositories/__tests__/chat_media_cache_helpers.test.ts

@@ -0,0 +1,120 @@
+import { describe, expect, it } from "vitest";
+
+import { ChatMessage, ChatSendResponse } from "@/data/dto/chat";
+
+import {
+  buildChatMediaCacheKey,
+  fallbackChatMediaMimeType,
+  getMessageMediaTargets,
+  getSendResponseMediaTargets,
+  uniqueMediaTargets,
+} from "../chat_media_cache_helpers";
+
+function makeMessage(
+  overrides: Partial<Parameters<typeof ChatMessage.from>[0]> = {},
+): ChatMessage {
+  return ChatMessage.from({
+    id: "msg-1",
+    role: "assistant",
+    type: "image",
+    content: "",
+    createdAt: "2026-06-30T00:00:00.000Z",
+    audioUrl: null,
+    image: { type: null, url: null },
+    lockDetail: {
+      locked: false,
+      showContent: true,
+      showUpgrade: false,
+      reason: null,
+      hint: null,
+      detail: null,
+    },
+    ...overrides,
+  });
+}
+
+function makeResponse(
+  overrides: Partial<Parameters<typeof ChatSendResponse.from>[0]> = {},
+): ChatSendResponse {
+  return ChatSendResponse.from({
+    reply: "",
+    audioUrl: "",
+    messageId: "msg-1",
+    isGuest: false,
+    timestamp: 1782356425363,
+    image: { type: null, url: null },
+    lockDetail: {
+      locked: false,
+      showContent: true,
+      showUpgrade: false,
+      reason: null,
+      hint: null,
+      detail: null,
+    },
+    ...overrides,
+  });
+}
+
+describe("chat media cache helpers", () => {
+  it("builds owner-scoped media cache keys", () => {
+    expect(
+      buildChatMediaCacheKey({
+        ownerKey: "user:u1",
+        messageId: "msg-1",
+        kind: "image",
+      }),
+    ).toBe("user:u1:msg-1:image");
+  });
+
+  it("extracts cacheable media targets from history messages", () => {
+    expect(
+      getMessageMediaTargets(
+        makeMessage({
+          audioUrl: "https://example.com/a.mp3",
+          image: { type: "jpg", url: "https://example.com/a.jpg" },
+        }),
+      ),
+    ).toEqual([
+      {
+        messageId: "msg-1",
+        kind: "image",
+        remoteUrl: "https://example.com/a.jpg",
+      },
+      {
+        messageId: "msg-1",
+        kind: "audio",
+        remoteUrl: "https://example.com/a.mp3",
+      },
+    ]);
+  });
+
+  it("ignores empty message ids and non-remote media urls", () => {
+    expect(
+      getSendResponseMediaTargets(
+        makeResponse({
+          messageId: "",
+          audioUrl: "https://example.com/a.mp3",
+          image: { type: "png", url: "data:image/png;base64,abc" },
+        }),
+      ),
+    ).toEqual([]);
+  });
+
+  it("deduplicates media targets", () => {
+    expect(
+      uniqueMediaTargets([
+        { messageId: "msg-1", kind: "image", remoteUrl: "https://x/a.jpg" },
+        { messageId: "msg-1", kind: "image", remoteUrl: "https://x/a.jpg" },
+        { messageId: "msg-1", kind: "audio", remoteUrl: "https://x/a.jpg" },
+      ]),
+    ).toEqual([
+      { messageId: "msg-1", kind: "image", remoteUrl: "https://x/a.jpg" },
+      { messageId: "msg-1", kind: "audio", remoteUrl: "https://x/a.jpg" },
+    ]);
+  });
+
+  it("provides fallback mime types", () => {
+    expect(fallbackChatMediaMimeType("image")).toBe("image/*");
+    expect(fallbackChatMediaMimeType("audio")).toBe("audio/mpeg");
+  });
+});

src/data/repositories/chat_media_cache_helpers.ts

@@ -0,0 +1,89 @@
+import type {
+  ChatMediaKind,
+  ChatMessage,
+  ChatSendResponse,
+} from "@/data/dto/chat";
+import type { CacheRemoteChatMediaInput } from "@/data/repositories/interfaces";
+import { isCacheableRemoteChatMediaUrl } from "@/lib/chat/chat_media_url";
+
+export { isCacheableRemoteChatMediaUrl };
+
+export function buildChatMediaCacheKey(input: {
+  ownerKey: string;
+  messageId: string;
+  kind: ChatMediaKind;
+}): string {
+  return `${input.ownerKey}:${input.messageId}:${input.kind}`;
+}
+
+export function getMessageMediaTargets(
+  message: ChatMessage,
+): CacheRemoteChatMediaInput[] {
+  const targets: CacheRemoteChatMediaInput[] = [];
+  pushMediaTarget(targets, {
+    messageId: message.id,
+    kind: "image",
+    remoteUrl: message.image.url,
+  });
+  pushMediaTarget(targets, {
+    messageId: message.id,
+    kind: "audio",
+    remoteUrl: message.audioUrl,
+  });
+  return targets;
+}
+
+export function getSendResponseMediaTargets(
+  response: ChatSendResponse,
+): CacheRemoteChatMediaInput[] {
+  const targets: CacheRemoteChatMediaInput[] = [];
+  pushMediaTarget(targets, {
+    messageId: response.messageId,
+    kind: "image",
+    remoteUrl: response.image.url,
+  });
+  pushMediaTarget(targets, {
+    messageId: response.messageId,
+    kind: "audio",
+    remoteUrl: response.audioUrl,
+  });
+  return targets;
+}
+
+export function fallbackChatMediaMimeType(kind: ChatMediaKind): string {
+  return kind === "image" ? "image/*" : "audio/mpeg";
+}
+
+export function uniqueMediaTargets(
+  targets: readonly CacheRemoteChatMediaInput[],
+): CacheRemoteChatMediaInput[] {
+  const seen = new Set<string>();
+  return targets.filter((target) => {
+    const key = `${target.messageId}:${target.kind}:${target.remoteUrl}`;
+    if (seen.has(key)) return false;
+    seen.add(key);
+    return true;
+  });
+}
+
+function pushMediaTarget(
+  targets: CacheRemoteChatMediaInput[],
+  input: {
+    messageId: string;
+    kind: ChatMediaKind;
+    remoteUrl: string | null;
+  },
+): void {
+  if (input.messageId.length === 0) return;
+  if (
+    !input.remoteUrl ||
+    !isCacheableRemoteChatMediaUrl(input.remoteUrl)
+  ) {
+    return;
+  }
+  targets.push({
+    messageId: input.messageId,
+    kind: input.kind,
+    remoteUrl: input.remoteUrl,
+  });
+}

src/data/repositories/chat_repository.ts

@@ -22,10 +22,18 @@ import {
   LocalChatMediaStorage,
   LocalChatStorage,
   LocalMessage,
-  type LocalChatMediaKind,
   type LocalChatMediaRow,
 } from "@/data/storage/chat";
+import {
+  buildChatMediaCacheKey,
+  fallbackChatMediaMimeType,
+  getMessageMediaTargets,
+  getSendResponseMediaTargets,
+  isCacheableRemoteChatMediaUrl,
+  uniqueMediaTargets,
+} from "./chat_media_cache_helpers";
 import { createLazySingleton } from "./lazy_singleton";
+import { requestBrowserPersistentStorageOnce } from "@/lib/browser/persistent_storage";
 
 const log = new Logger("DataRepositoriesChatRepository");
 
@@ -180,7 +188,7 @@ export class ChatRepository implements IChatRepository {
     input: CacheRemoteChatMediaInput,
   ): Promise<Result<LocalChatMediaRow>> {
     return Result.wrap(async () => {
-      if (!isCacheableRemoteUrl(input.remoteUrl)) {
+      if (!isCacheableRemoteChatMediaUrl(input.remoteUrl)) {
         throw new Error(`Unsupported media url: ${input.remoteUrl}`);
       }
 
@@ -217,10 +225,12 @@ export class ChatRepository implements IChatRepository {
         remoteUrl: input.remoteUrl,
         blob,
         mimeType:
-          blob.type || response.headers.get("content-type") || fallbackMimeType(input.kind),
+          blob.type ||
+          response.headers.get("content-type") ||
+          fallbackChatMediaMimeType(input.kind),
       });
       if (Result.isErr(saveResult)) throw saveResult.error;
-      void requestPersistentStorage();
+      void requestBrowserPersistentStorageOnce();
 
       const savedResult = await this.mediaStorage.getMedia(cacheKey);
       if (Result.isErr(savedResult)) throw savedResult.error;
@@ -333,7 +343,11 @@ export class ChatRepository implements IChatRepository {
     ownerKey: string,
     input: ChatMediaLookupInput,
   ): string {
-    return `${ownerKey}:${input.messageId}:${input.kind}`;
+    return buildChatMediaCacheKey({
+      ownerKey,
+      messageId: input.messageId,
+      kind: input.kind,
+    });
   }
 }
 
@@ -346,90 +360,3 @@ export const getChatRepository = createLazySingleton<IChatRepository>(
       LocalChatMediaStorage.getInstance(),
     ),
 );
-
-function getMessageMediaTargets(
-  message: ChatMessage,
-): CacheRemoteChatMediaInput[] {
-  const targets: CacheRemoteChatMediaInput[] = [];
-  pushMediaTarget(targets, {
-    messageId: message.id,
-    kind: "image",
-    remoteUrl: message.image.url,
-  });
-  pushMediaTarget(targets, {
-    messageId: message.id,
-    kind: "audio",
-    remoteUrl: message.audioUrl,
-  });
-  return targets;
-}
-
-function getSendResponseMediaTargets(
-  response: ChatSendResponse,
-): CacheRemoteChatMediaInput[] {
-  const targets: CacheRemoteChatMediaInput[] = [];
-  pushMediaTarget(targets, {
-    messageId: response.messageId,
-    kind: "image",
-    remoteUrl: response.image.url,
-  });
-  pushMediaTarget(targets, {
-    messageId: response.messageId,
-    kind: "audio",
-    remoteUrl: response.audioUrl,
-  });
-  return targets;
-}
-
-function pushMediaTarget(
-  targets: CacheRemoteChatMediaInput[],
-  input: {
-    messageId: string;
-    kind: LocalChatMediaKind;
-    remoteUrl: string | null;
-  },
-): void {
-  if (input.messageId.length === 0) return;
-  if (!input.remoteUrl || !isCacheableRemoteUrl(input.remoteUrl)) return;
-  targets.push({
-    messageId: input.messageId,
-    kind: input.kind,
-    remoteUrl: input.remoteUrl,
-  });
-}
-
-function isCacheableRemoteUrl(url: string): boolean {
-  return url.startsWith("http://") || url.startsWith("https://");
-}
-
-function fallbackMimeType(kind: LocalChatMediaKind): string {
-  return kind === "image" ? "image/*" : "audio/mpeg";
-}
-
-function uniqueMediaTargets(
-  targets: readonly CacheRemoteChatMediaInput[],
-): CacheRemoteChatMediaInput[] {
-  const seen = new Set<string>();
-  return targets.filter((target) => {
-    const key = `${target.messageId}:${target.kind}:${target.remoteUrl}`;
-    if (seen.has(key)) return false;
-    seen.add(key);
-    return true;
-  });
-}
-
-let storagePersistenceRequested = false;
-
-async function requestPersistentStorage(): Promise<void> {
-  if (storagePersistenceRequested) return;
-  storagePersistenceRequested = true;
-  if (typeof navigator === "undefined") return;
-  if (!navigator.storage?.persist) return;
-
-  try {
-    const persisted = await navigator.storage.persist();
-    log.debug("[chat-media] persistent storage requested", { persisted });
-  } catch (error) {
-    log.debug("[chat-media] persistent storage request skipped", { error });
-  }
-}

src/data/repositories/interfaces/ichat_repository.ts

@@ -14,19 +14,17 @@
 import type { Result } from "@/utils";
 import type {
   ChatHistoryResponse,
+  ChatMediaKind,
   ChatMessage,
   ChatSendResponse,
   UnlockHistoryResponse,
   UnlockPrivateResponse,
 } from "@/data/dto/chat";
-import type {
+import type { LocalChatMediaRow } from "@/data/storage/chat";
-  LocalChatMediaKind,
-  LocalChatMediaRow,
-} from "@/data/storage/chat";
 
 export interface ChatMediaLookupInput {
   messageId: string;
-  kind: LocalChatMediaKind;
+  kind: ChatMediaKind;
 }
 
 export interface CacheRemoteChatMediaInput extends ChatMediaLookupInput {

src/data/storage/chat/local_chat_db.ts

@@ -12,6 +12,7 @@
  */
 
 import Dexie, { type Table } from "dexie";
+import type { ChatMediaKind } from "@/data/dto/chat";
 import type {
   ChatImageData,
   ChatLockDetailData,
@@ -32,13 +33,11 @@ export interface LocalMessageRow {
   sessionId: string;
 }
 
-export type LocalChatMediaKind = "image" | "audio";
-
 export interface LocalChatMediaRow {
   cacheKey: string;
   ownerKey: string;
   messageId: string;
-  kind: LocalChatMediaKind;
+  kind: ChatMediaKind;
   remoteUrl: string;
   blob: Blob;
   mimeType: string;

src/data/storage/chat/local_chat_media_storage.ts

@@ -1,20 +1,20 @@
 "use client";
 
 import { Result, type Result as ResultT } from "@/utils";
+import type { ChatMediaKind } from "@/data/dto/chat";
 
 import {
   LocalChatDB,
-  type LocalChatMediaKind,
   type LocalChatMediaRow,
 } from "./local_chat_db";
 
-export type { LocalChatMediaKind, LocalChatMediaRow };
+export type { LocalChatMediaRow };
 
 export interface SaveLocalChatMediaInput {
   cacheKey: string;
   ownerKey: string;
   messageId: string;
-  kind: LocalChatMediaKind;
+  kind: ChatMediaKind;
   remoteUrl: string;
   blob: Blob;
   mimeType: string;

src/lib/browser/persistent_storage.ts

@@ -0,0 +1,20 @@
+"use client";
+
+import { Logger } from "@/utils";
+
+const log = new Logger("LibBrowserPersistentStorage");
+let storagePersistenceRequested = false;
+
+export async function requestBrowserPersistentStorageOnce(): Promise<void> {
+  if (storagePersistenceRequested) return;
+  storagePersistenceRequested = true;
+  if (typeof navigator === "undefined") return;
+  if (!navigator.storage?.persist) return;
+
+  try {
+    const persisted = await navigator.storage.persist();
+    log.debug("[persistent-storage] requested", { persisted });
+  } catch (error) {
+    log.debug("[persistent-storage] request skipped", { error });
+  }
+}

src/lib/chat/__tests__/chat_media_url.test.ts

@@ -0,0 +1,44 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  isBrowserLocalChatImageSource,
+  isCacheableRemoteChatMediaUrl,
+  normalizeChatImageSource,
+} from "../chat_media_url";
+
+describe("chat media url helpers", () => {
+  it("detects cacheable remote media urls", () => {
+    expect(isCacheableRemoteChatMediaUrl("https://example.com/a.jpg")).toBe(
+      true,
+    );
+    expect(isCacheableRemoteChatMediaUrl("http://example.com/a.jpg")).toBe(
+      true,
+    );
+    expect(isCacheableRemoteChatMediaUrl("blob:http://app/media")).toBe(false);
+    expect(isCacheableRemoteChatMediaUrl("data:image/png;base64,abc")).toBe(
+      false,
+    );
+  });
+
+  it("normalizes bare base64 image payloads", () => {
+    expect(normalizeChatImageSource("abc123")).toBe(
+      "data:image/png;base64,abc123",
+    );
+    expect(normalizeChatImageSource("blob:http://app/media")).toBe(
+      "blob:http://app/media",
+    );
+    expect(normalizeChatImageSource("https://example.com/a.jpg")).toBe(
+      "https://example.com/a.jpg",
+    );
+  });
+
+  it("detects image sources that should bypass Next image optimization", () => {
+    expect(isBrowserLocalChatImageSource("blob:http://app/media")).toBe(true);
+    expect(isBrowserLocalChatImageSource("data:image/png;base64,abc")).toBe(
+      true,
+    );
+    expect(isBrowserLocalChatImageSource("https://example.com/a.jpg")).toBe(
+      false,
+    );
+  });
+});

src/lib/chat/chat_media_cache_client.ts

@@ -0,0 +1,31 @@
+"use client";
+
+import type { ChatMediaKind } from "@/data/dto/chat";
+import { getChatRepository } from "@/data/repositories/chat_repository";
+import { Result, type Result as ResultT } from "@/utils";
+
+export interface ResolveCachedChatMediaBlobInput {
+  messageId: string;
+  kind: ChatMediaKind;
+}
+
+export interface CacheRemoteChatMediaBlobInput
+  extends ResolveCachedChatMediaBlobInput {
+  remoteUrl: string;
+}
+
+export async function resolveCachedChatMediaBlob(
+  input: ResolveCachedChatMediaBlobInput,
+): Promise<ResultT<Blob | null>> {
+  const result = await getChatRepository().getCachedMedia(input);
+  if (Result.isErr(result)) return result;
+  return Result.ok(result.data?.blob ?? null);
+}
+
+export async function cacheRemoteChatMediaBlob(
+  input: CacheRemoteChatMediaBlobInput,
+): Promise<ResultT<Blob>> {
+  const result = await getChatRepository().cacheRemoteMedia(input);
+  if (Result.isErr(result)) return result;
+  return Result.ok(result.data.blob);
+}

src/lib/chat/chat_media_url.ts

@@ -0,0 +1,18 @@
+export function isCacheableRemoteChatMediaUrl(url: string): boolean {
+  return url.startsWith("http://") || url.startsWith("https://");
+}
+
+export function normalizeChatImageSource(url: string): string {
+  if (
+    url.startsWith("data:") ||
+    url.startsWith("http") ||
+    url.startsWith("blob:")
+  ) {
+    return url;
+  }
+  return `data:image/png;base64,${url}`;
+}
+
+export function isBrowserLocalChatImageSource(src: string): boolean {
+  return src.startsWith("blob:") || src.startsWith("data:");
+}

src/lib/chat/use_cached_chat_media_url.ts

@@ -2,14 +2,19 @@
 
 import { useEffect, useState } from "react";
 
-import type { LocalChatMediaKind } from "@/data/storage/chat";
+import type { ChatMediaKind } from "@/data/dto/chat";
-import { getChatRepository } from "@/data/repositories/chat_repository";
 import { Result } from "@/utils";
 
+import {
+  cacheRemoteChatMediaBlob,
+  resolveCachedChatMediaBlob,
+} from "./chat_media_cache_client";
+import { isCacheableRemoteChatMediaUrl } from "./chat_media_url";
+
 export interface UseCachedChatMediaUrlInput {
   messageId?: string | null;
   remoteUrl?: string | null;
-  kind: LocalChatMediaKind;
+  kind: ChatMediaKind;
 }
 
 export interface UseCachedChatMediaUrlOutput {
@@ -35,7 +40,11 @@ export function useCachedChatMediaUrl({
     messageId && remoteUrl ? `${messageId}:${kind}:${remoteUrl}` : "";
 
   useEffect(() => {
-    if (!messageId || !remoteUrl || !isCacheableRemoteUrl(remoteUrl)) {
+    if (
+      !messageId ||
+      !remoteUrl ||
+      !isCacheableRemoteChatMediaUrl(remoteUrl)
+    ) {
       return;
     }
 
@@ -59,16 +68,18 @@ export function useCachedChatMediaUrl({
     };
 
     const resolveCachedMedia = async () => {
-      const chatRepo = getChatRepository();
+      const cachedResult = await resolveCachedChatMediaBlob({
-      const cachedResult = await chatRepo.getCachedMedia({ messageId, kind });
+        messageId,
+        kind,
+      });
       if (cancelled) return;
 
       if (Result.isOk(cachedResult) && cachedResult.data) {
-        applyBlob(cachedResult.data.blob);
+        applyBlob(cachedResult.data);
         return;
       }
 
-      const cacheResult = await chatRepo.cacheRemoteMedia({
+      const cacheResult = await cacheRemoteChatMediaBlob({
         messageId,
         kind,
         remoteUrl,
@@ -76,7 +87,7 @@ export function useCachedChatMediaUrl({
       if (cancelled) return;
 
       if (Result.isOk(cacheResult)) {
-        applyBlob(cacheResult.data.blob);
+        applyBlob(cacheResult.data);
       }
     };
 
@@ -100,7 +111,3 @@ export function useCachedChatMediaUrl({
     isUsingCachedMedia: false,
   };
 }
-
-function isCacheableRemoteUrl(url: string): boolean {
-  return url.startsWith("http://") || url.startsWith("https://");
-}

src/stores/chat/chat-machine.actors.ts

@@ -67,6 +67,7 @@ export const loadMoreHistoryActor = fromPromise<
     throw result.error;
   }
   const page = localMessagesToUi(result.data.messages);
+  void chatRepo.prefetchMediaForMessages(result.data.messages);
   return {
     messages: page,
     hasMore: page.length >= PAGE_SIZE,