diff --git a/web/src/lib/api/client.ts b/web/src/lib/api/client.ts
index 0990e4cc..76a0de63 100644
--- a/web/src/lib/api/client.ts
+++ b/web/src/lib/api/client.ts
@@ -92,13 +92,13 @@ export function translateReason(reason: string | undefined, details?: unknown):
   return (typeof entry === 'function' ? entry(details) : entry) || null;
 }
 
-function requestId(): string {
+export function requestId(): string {
   return typeof crypto !== 'undefined' && crypto.randomUUID
     ? crypto.randomUUID()
     : `web_${Date.now().toString(36)}_${Math.random().toString(36).slice(2)}`;
 }
 
-function apiBase(): string {
+export function apiBase(): string {
   const endpoints = useSessionStore.getState().tenant?.endpoints;
   return (endpoints?.api || DEFAULT_API_BASE).replace(/\/$/, '');
 }
diff --git a/web/src/lib/api/friends.ts b/web/src/lib/api/friends.ts
index f507988c..1bc8852f 100644
--- a/web/src/lib/api/friends.ts
+++ b/web/src/lib/api/friends.ts
@@ -65,11 +65,11 @@ export function getFriendRequests() {
 }
 
 export function acceptFriendRequest(requestId: string, version?: number) {
-  return imPost<void>(`/friend-requests/${encodeURIComponent(requestId)}/accept`, version ? { version } : {});
+  return imPost<void>(`/friend-requests/${encodeURIComponent(requestId)}/accept`, version !== undefined ? { version } : {});
 }
 
 export function rejectFriendRequest(requestId: string, version?: number) {
-  return imPost<void>(`/friend-requests/${encodeURIComponent(requestId)}/reject`, version ? { version } : {});
+  return imPost<void>(`/friend-requests/${encodeURIComponent(requestId)}/reject`, version !== undefined ? { version } : {});
 }
 
 export interface ConversationSettings {
diff --git a/web/src/lib/api/upload.ts b/web/src/lib/api/upload.ts
index a4047ebd..c85716a3 100644
--- a/web/src/lib/api/upload.ts
+++ b/web/src/lib/api/upload.ts
@@ -1,9 +1,16 @@
 // The file HTTP endpoint (docs/IM-前后端对接文档.md:62,460-461) is a SEPARATE surface from
-// /v1/im/* -- it lives at the tenant's `file` base URL, and authenticates with a different header
-// (`X-MeetingIM-Auth: token <token>`) than the REST API's `Authorization: Bearer`, matching
-// upstream Tinode's own LargeFileHelper convention. The token value is the same session token
-// either way, just carried differently.
+// /v1/im/* -- it lives at the tenant's `file` base URL and speaks Tinode's native {ctrl} protocol,
+// not the REST /v1/im envelope. Its auth header is `Authorization: Token <token>` (capitalized
+// scheme, standard header name) -- NOT `X-MeetingIM-Auth: token <token>` as the protocol doc
+// describes. This was corrected against the old app's own upload code, whose comment explicitly
+// states the header/scheme were "verified live against the real server, not just read from source"
+// (it also separately warns that the SDK's own built-in LargeFileHelper.upload() gets this WRONG
+// for this backend, sending 'X-Tinode-APIKey'/'X-Tinode-Auth' headers the server doesn't recognize
+// at all -- so this hand-built fetch, not the SDK helper, is the only path that actually works here).
+import { API_KEY } from '@/lib/config';
+
 import { authToken, fileBase } from './client';
+import { getTinode } from '../tinode/connection';
 
 export interface UploadedFile {
   url: string;
@@ -12,16 +19,32 @@ export interface UploadedFile {
   mime: string;
 }
 
+/**
+ * ctrl.text values a failure here can actually carry (Tinode's native protocol, not the REST
+ * layer's `reason` codes -- client.ts's REASON_MESSAGES table never applies to this endpoint).
+ */
+const UPLOAD_CTRL_TEXT_CN: Record<string, string> = {
+  'too large': '文件大小超出限制',
+  malformed: '请求内容有误，请稍后重试',
+  'permission denied': '没有权限执行此操作',
+  gone: '内容不存在或已被删除',
+  'not found': '内容不存在或已被删除',
+};
+
 export async function uploadFile(file: File, topic?: string): Promise<UploadedFile> {
   const form = new FormData();
   form.append('file', file);
+  form.set('id', getTinode().getNextUniqueId());
   if (topic) {
     form.append('purpose', 'chat_file');
     form.append('topic', topic);
   }
   const res = await fetch(`${fileBase()}/u/`, {
     method: 'POST',
-    headers: { 'X-MeetingIM-Auth': `token ${authToken()}` },
+    headers: {
+      'X-MeetingIM-APIKey': API_KEY,
+      Authorization: `Token ${authToken()}`,
+    },
     body: form,
   });
   const text = await res.text();
@@ -32,11 +55,18 @@ export async function uploadFile(file: File, topic?: string): Promise<UploadedFi
     throw new Error('文件上传失败：服务器返回异常');
   }
   if (!res.ok || !payload.ctrl || payload.ctrl.code >= 300 || !payload.ctrl.params) {
-    throw new Error(payload.ctrl?.text || '文件上传失败');
+    const rawText = payload.ctrl?.text?.trim().toLowerCase();
+    throw new Error((rawText && UPLOAD_CTRL_TEXT_CN[rawText]) || payload.ctrl?.text || '文件上传失败');
   }
   return payload.ctrl.params;
 }
 
+/** Headers needed to fetch a file this endpoint serves (see AttachmentPreview.tsx's authenticated
+ *  blob-URL fetch) -- same scheme as uploadFile's own auth, kept in one place so they can't drift. */
+export function fileAuthHeaders(): Record<string, string> {
+  return { 'X-MeetingIM-APIKey': API_KEY, Authorization: `Token ${authToken()}` };
+}
+
 /**
  * Absolute download URL for a file reference returned by uploadFile() or a received attachment.
  * The upload response's `url` (e.g. "/v0/file/s/file123") is already rooted at the tenant's file
diff --git a/web/src/lib/messages/preview.ts b/web/src/lib/messages/preview.ts
index a493c6cf..f241a8f8 100644
--- a/web/src/lib/messages/preview.ts
+++ b/web/src/lib/messages/preview.ts
@@ -1,5 +1,7 @@
 import { Drafty, type DraftyContent, type StoredMessage } from 'tinode-sdk';
 
+import { isServerDeleted } from '@/lib/messages/dispatch';
+
 /**
  * One-line chat-list preview text (README §2.1): plain text renders as-is, everything else falls
  * back to a bracketed type label. Own messages get a "我：" prefix. Grown incrementally -- VC (call)
@@ -10,7 +12,10 @@ export function formatMessagePreview(msg: StoredMessage | undefined, myUserId: s
   if (!msg) return '';
   const prefix = msg.from && myUserId && msg.from === myUserId ? '我：' : '';
   const content = msg.content;
-  if (content == null) return `${prefix}[消息已删除]`;
+  // `msg.hi` (server soft-delete) is checked unconditionally, before any content check -- the old
+  // app's own equivalent renderer does the same, since a hi-flagged message can still carry
+  // non-null content that must NOT leak into this preview.
+  if (isServerDeleted(msg) || content == null) return `${prefix}[消息已删除]`;
   if (typeof content === 'string' || Drafty.isPlainText(content)) {
     return prefix + Drafty.toPlainText(content);
   }
diff --git a/web/src/lib/tinode/attachments.ts b/web/src/lib/tinode/attachments.ts
index 2d702b51..5e20e94a 100644
--- a/web/src/lib/tinode/attachments.ts
+++ b/web/src/lib/tinode/attachments.ts
@@ -75,8 +75,14 @@ export async function sendVoice(topic: Topic, blob: Blob, durationMs: number): P
   const file = new File([blob], `voice.${blob.type.includes('mp4') ? 'm4a' : 'webm'}`, { type: blob.type });
   const content =
     file.size <= MAX_INBAND_ATTACHMENT_SIZE
-      ? Drafty.insertAudio(undefined, 0, { mime: file.type, bits: await fileToBase64(file), duration: durationMs, size: file.size })
-      : Drafty.insertAudio(undefined, 0, { mime: file.type, refurl: (await uploadFile(file, topic.name)).url, duration: durationMs, size: file.size });
+      ? Drafty.insertAudio(undefined, 0, { mime: file.type, bits: await fileToBase64(file), duration: durationMs, size: file.size, filename: file.name })
+      : Drafty.insertAudio(undefined, 0, {
+          mime: file.type,
+          refurl: (await uploadFile(file, topic.name)).url,
+          duration: durationMs,
+          size: file.size,
+          filename: file.name,
+        });
   const msg = topic.createMessage(content, false);
   msg.head = Object.assign(msg.head || {}, { 'x-im-type': 'voice' });
   return topic.publishDraft(msg, Promise.resolve());
diff --git a/web/src/lib/tinode/tinode-sdk.d.ts b/web/src/lib/tinode/tinode-sdk.d.ts
index 48d550b2..b589131c 100644
--- a/web/src/lib/tinode/tinode-sdk.d.ts
+++ b/web/src/lib/tinode/tinode-sdk.d.ts
@@ -47,9 +47,11 @@ declare module 'tinode-sdk' {
   }
 
   export class AccessMode {
-    mode: string;
-    given: string;
-    want: string;
+    /** Numeric bitmasks at runtime (tinode.dev.js:26-33's AccessMode.decode()), NOT the "JRWPS"-style
+     *  strings that only come out of getMode()/getGiven()/getWant()/toString(). */
+    mode: number;
+    given: number;
+    want: number;
     isOwner(): boolean;
     isAdmin(): boolean;
     isSharer(): boolean;
@@ -234,6 +236,13 @@ declare module 'tinode-sdk' {
     contacts(callback: (contact: Contact) => void): void;
     pinnedTopicRank(topic: string): number;
     getMeta(query: unknown): Promise<unknown>;
+    /**
+     * Fires when a contact's read/recv/unread state changes via `Topic.note()` (the base `noteRead`/
+     * noteRecv` path -- confirmed against tinode.dev.js's `TopicMe._refreshContact`/`Topic.note`):
+     * that path calls ONLY this callback, not `onData`/`onInfo`/`onPres`. Marking a conversation read
+     * (`topic.noteRead(0)`) updates the contact's unread count via this callback alone.
+     */
+    onContactUpdate?: (what: string, contact: Contact) => void;
   }
 
   export class Tinode {
@@ -248,6 +257,9 @@ declare module 'tinode-sdk' {
     disconnect(): void;
     /** Skips the remaining exponential-backoff wait and retries the connection now. */
     reconnect(force?: boolean): void;
+    /** Monotonically-increasing per-connection request id string; the file-upload endpoint's own
+     *  multipart form expects one in an `id` field (mirrors the SDK's own LargeFileHelper). */
+    getNextUniqueId(): string;
     isConnected(): boolean;
     isAuthenticated(): boolean;
     getCurrentUserID(): string;
@@ -293,13 +305,14 @@ declare module 'tinode-sdk' {
     onLogin?: (code: number, text: string) => void;
     onNetworkProbe?: () => void;
     /**
-     * Fires on every SDK-internal reconnect attempt. `seconds` is the SDK's own next-retry countdown
-     * (exponential backoff, ~2s base doubling up to 10 iterations, +/-30% jitter -- entirely internal
-     * to the SDK, this app does not implement its own backoff). `promise` is only present while a
-     * retry is actually in flight; when absent, the app is expected to run its own 1s countdown
-     * display down to the next attempt.
+     * Fires on every SDK-internal reconnect attempt. `timeoutMs` is the SDK's own next-retry
+     * countdown IN MILLISECONDS (exponential backoff, 2000ms base doubling up to 10 iterations,
+     * +/-30% jitter -- entirely internal to the SDK, verified against tinode.dev.js:451-456,553-556;
+     * this app does not implement its own backoff, only its own 1s display tick off this one value).
+     * `promise` is only present while a retry is actually in flight; `timeoutMs < 0` means retrying
+     * has stopped entirely (e.g. an explicit disconnect).
      */
-    onAutoreconnectIteration?: (seconds: number, promise?: Promise<unknown>) => void;
+    onAutoreconnectIteration?: (timeoutMs: number, promise?: Promise<unknown>) => void;
   }
 
   export const Drafty: {
@@ -312,7 +325,14 @@ declare module 'tinode-sdk' {
     isPlainText(content: DraftyContent | string): boolean;
     hasEntities(content: DraftyContent | string): boolean;
     entities(content: DraftyContent | string, callback: (data: Record<string, unknown> | undefined) => void, context?: unknown): void;
-    /** Deep-copies `content` and strips anything the server would reject when re-sent (e.g. as a quote/forward payload). */
+    /**
+     * MUTATES `content` in place (tinode.dev.js:2573-2588) -- only each entity's `.data` gets
+     * replaced with a fresh shallow copy; the document itself, its `.ent` array, and each entity
+     * wrapper are the SAME objects passed in, not a deep copy. Callers that need to preserve the
+     * original (e.g. a still-displayed message) must clone before calling this, same as this app's
+     * own send.ts already does (`JSON.parse(JSON.stringify(...))`) -- don't drop that clone trusting
+     * this function to have done it.
+     */
     sanitizeEntities(content: DraftyContent): DraftyContent;
     /** Concatenates two Drafty documents, remapping `fmt[].key` entity indices in `second`. */
     append(first: DraftyContent | undefined, second: DraftyContent): DraftyContent;
diff --git a/web/src/lib/tinode/topics.ts b/web/src/lib/tinode/topics.ts
index 7cbe34f7..c5c839c3 100644
--- a/web/src/lib/tinode/topics.ts
+++ b/web/src/lib/tinode/topics.ts
@@ -75,6 +75,11 @@ export function getMessagesSnapshot(topicName: string): StoredMessage[] {
 export function subscribeMeTopic(): Promise<unknown> {
   const me = getTinode().getMeTopic();
   wireTopicCallbacks(me);
+  // Read/recv/unread updates (e.g. from noteRead() when opening a conversation) travel through
+  // TopicMe's OWN single-slot callback, separate from onData/onInfo/onPres -- wireTopicCallbacks
+  // doesn't touch it. Without this, the chat list's unread badge/ordering goes stale after reading
+  // a conversation until some unrelated topic event happens to invalidate its cached snapshot.
+  me.onContactUpdate = () => notifyTopic(me.name);
   return me.subscribe(me.startMetaQuery().withLaterSub().withDesc().withTags().withCred().build());
 }