feat(web): voice messages (record, send, playback)

Click-to-record (README §3.3's explicit 取消/发送 buttons), not the old
app's press-and-hold-with-swipe-to-cancel gesture -- the new design replaces
that touch gesture with plain buttons, a reasonable desktop-first
adaptation; the underlying MediaRecorder mechanics (audio/webm or
audio/mp4 depending on browser support, 24kbps, 2s minimum/10min maximum
duration) are ported as-is from the old app's audio-recorder.jsx.

- VoiceRecorder.tsx: recording UI + MediaRecorder lifecycle. Silently
  discards (no send) recordings under MIN_DURATION, matching the old app.
  Deliberately skips the `webm-duration-fix` package the old app pulled in
  for Chrome's well-known missing-webm-duration-metadata bug -- this app's
  own displayed duration comes from its own recording timer, not the file's
  embedded metadata, so only a browser's native <audio> scrubber would be
  affected, not anything this app actually shows.
- attachments.ts: sendVoice() -- inline base64 or upload-then-reference,
  same size-based branch as images/files, Drafty.insertAudio's confirmed
  {mime,val/ref,duration,size} shape.
- AttachmentPreview.tsx: AudioAttachment play/pause button + static
  waveform (CSS repeating-gradient, not real waveform analysis) + duration.

Verified the failure path live (this sandbox blocks getUserMedia): the
recorder's error state shows a clear message and recovers cleanly back to
the normal composer with no crash. The actual record -> encode -> send ->
playback round trip could not be exercised in this environment and needs
a manual check with real microphone access.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

web/src/features/messages/AttachmentPreview.tsx

@@ -100,3 +100,50 @@ export function FileAttachment({ data }: { data: FileData }) {
     </a>
   );
 }
+
+interface AudioData {
+  val?: string;
+  ref?: string;
+  mime?: string;
+  duration?: number;
+}
+
+function formatAudioDuration(ms: number | undefined): string {
+  const totalSeconds = Math.round((ms || 0) / 1000);
+  return `${Math.floor(totalSeconds / 60)}:${String(totalSeconds % 60).padStart(2, '0')}`;
+}
+
+export function AudioAttachment({ data }: { data: AudioData }) {
+  const inline = typeof data.val === 'string' ? `data:${data.mime || 'audio/webm'};base64,${data.val}` : null;
+  const remote = useAuthedBlobUrl(inline ? undefined : data.ref);
+  const src = inline || remote.url;
+  const [playing, setPlaying] = useState(false);
+  const [audioEl] = useState(() => (typeof Audio !== 'undefined' ? new Audio() : null));
+
+  useEffect(() => {
+    if (!audioEl) return undefined;
+    const onEnded = () => setPlaying(false);
+    audioEl.addEventListener('ended', onEnded);
+    return () => audioEl.removeEventListener('ended', onEnded);
+  }, [audioEl]);
+
+  const toggle = () => {
+    if (!audioEl || !src) return;
+    if (playing) {
+      audioEl.pause();
+      setPlaying(false);
+      return;
+    }
+    if (audioEl.src !== src) audioEl.src = src;
+    audioEl.play().catch(() => {});
+    setPlaying(true);
+  };
+
+  return (
+    <button type="button" onClick={toggle} disabled={!src} className="flex w-[200px] items-center gap-2">
+      <Icon name={playing ? 'pause_circle' : 'play_circle'} className="text-[24px] text-accent" />
+      <span className="h-4 flex-1 rounded bg-[repeating-linear-gradient(90deg,#b7c3d4_0px,#b7c3d4_2px,transparent_2px,transparent_5px)]" />
+      <span className="flex-none text-xs text-text-secondary">{remote.loading ? '…' : formatAudioDuration(data.duration)}</span>
+    </button>
+  );
+}

web/src/features/messages/ConversationView.tsx

@@ -9,13 +9,14 @@ import { EmojiPanel } from '@/features/messages/EmojiPanel';
 import { ForwardPickerModal } from '@/features/messages/ForwardPickerModal';
 import { MessageContextMenu } from '@/features/messages/MessageContextMenu';
 import { MessageRow } from '@/features/messages/MessageBubble';
+import { VoiceRecorder } from '@/features/messages/VoiceRecorder';
 import { useBootstrap } from '@/lib/api/hooks';
 import { favoriteMessages, recallMessage } from '@/lib/api/messages';
 import { avatarBgClass, avatarLetter } from '@/lib/avatar';
 import { FETCH_PAGE_TRIGGER, MESSAGES_PAGE } from '@/lib/config';
 import { availableActions, type MessageAction } from '@/lib/messages/actions';
 import { renderDrafty } from '@/lib/messages/drafty';
-import { sendFile, sendImage } from '@/lib/tinode/attachments';
+import { sendFile, sendImage, sendVoice } from '@/lib/tinode/attachments';
 import { useChatList, useTinode, useTopicMessages } from '@/lib/tinode/hooks';
 import { forwardMessage, sendReply, sendText } from '@/lib/tinode/send';
 import { closeConversation, openConversation } from '@/lib/tinode/topics';
@@ -45,6 +46,7 @@ export function ConversationView() {
   const [selectMode, setSelectMode] = useState(false);
   const [selectedSeqs, setSelectedSeqs] = useState<Set<number>>(new Set());
   const [loadingOlder, setLoadingOlder] = useState(false);
+  const [recording, setRecording] = useState(false);
   const [replyTo, setReplyTo] = useState<StoredMessage | null>(null);
   const [forwardMsg, setForwardMsg] = useState<StoredMessage | null>(null);
   const [emojiOpen, setEmojiOpen] = useState(false);
@@ -317,26 +319,44 @@ export function ConversationView() {
               <input type="file" onChange={handlePickFile} className="hidden" />
             </label>
             <Icon name="contact_page" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
-            <Icon name="mic_none" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
-            <Icon name="history" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
-          </div>
-          <textarea
-            value={draft}
-            onChange={(e) => setDraft(e.target.value)}
-            onKeyDown={handleKeyDown}
-            placeholder="输入消息，Enter 发送，Shift+Enter 换行"
-            className="min-h-[72px] w-full resize-none bg-transparent text-[15px] leading-normal outline-none placeholder:text-text-placeholder-1"
-          />
-          <div className="flex justify-end">
             <button
               type="button"
-              onClick={submit}
-              disabled={!draft.trim()}
-              className="h-9 rounded-lg bg-btn px-5.5 text-sm font-medium text-white shadow-btn disabled:bg-btn-disabled disabled:shadow-none"
+              onClick={() => setRecording(true)}
+              className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default"
             >
-              发送
+              <Icon name="mic_none" />
             </button>
+            <Icon name="history" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
           </div>
+          {recording ? (
+            <VoiceRecorder
+              onCancel={() => setRecording(false)}
+              onSend={(blob, durationMs) => {
+                setRecording(false);
+                sendVoice(topic, blob, durationMs).catch(() => {});
+              }}
+            />
+          ) : (
+            <>
+              <textarea
+                value={draft}
+                onChange={(e) => setDraft(e.target.value)}
+                onKeyDown={handleKeyDown}
+                placeholder="输入消息，Enter 发送，Shift+Enter 换行"
+                className="min-h-[72px] w-full resize-none bg-transparent text-[15px] leading-normal outline-none placeholder:text-text-placeholder-1"
+              />
+              <div className="flex justify-end">
+                <button
+                  type="button"
+                  onClick={submit}
+                  disabled={!draft.trim()}
+                  className="h-9 rounded-lg bg-btn px-5.5 text-sm font-medium text-white shadow-btn disabled:bg-btn-disabled disabled:shadow-none"
+                >
+                  发送
+                </button>
+              </div>
+            </>
+          )}
         </div>
       )}
 

web/src/features/messages/VoiceRecorder.tsx

@@ -0,0 +1,136 @@
+import { useEffect, useRef, useState } from 'react';
+
+import { Icon } from '@/app/Icon';
+import { MAX_DURATION, MIN_DURATION } from '@/lib/config';
+
+// Chrome/Firefox vs Safari support different codecs for MediaRecorder -- ported from the old app's
+// audio-recorder.jsx, first-supported-wins probe.
+const AUDIO_MIME_TYPES = ['audio/webm', 'audio/mp4', ''];
+
+function formatSeconds(s: number): string {
+  return `${Math.floor(s / 60)}:${String(s % 60).padStart(2, '0')}`;
+}
+
+interface VoiceRecorderProps {
+  onSend: (blob: Blob, durationMs: number) => void;
+  onCancel: () => void;
+}
+
+/**
+ * README §3.3's recording state: click-to-start (from the composer's mic icon), explicit 取消/发送
+ * buttons -- not the old app's press-and-hold-with-swipe-to-cancel gesture, which the new design
+ * replaces with plain buttons (a reasonable desktop-first adaptation; the underlying recording
+ * mechanics are the same). Silently cancels (no message sent) if the recording is shorter than
+ * MIN_DURATION, matching the old app's "too short, discard" behavior.
+ */
+export function VoiceRecorder({ onSend, onCancel }: VoiceRecorderProps) {
+  const [seconds, setSeconds] = useState(0);
+  const [ready, setReady] = useState(false);
+  const [error, setError] = useState('');
+  const recorderRef = useRef<MediaRecorder | null>(null);
+  const chunksRef = useRef<Blob[]>([]);
+  const streamRef = useRef<MediaStream | null>(null);
+  const startedAtRef = useRef(0);
+  const finishedRef = useRef(false);
+
+  const stopStream = () => {
+    streamRef.current?.getTracks().forEach((t) => t.stop());
+    streamRef.current = null;
+  };
+
+  const finish = (send: boolean) => {
+    if (finishedRef.current) return;
+    finishedRef.current = true;
+    const recorder = recorderRef.current;
+    if (!recorder || recorder.state === 'inactive') {
+      stopStream();
+      onCancel();
+      return;
+    }
+    const durationMs = Date.now() - startedAtRef.current;
+    recorder.onstop = () => {
+      stopStream();
+      if (send && durationMs >= MIN_DURATION) {
+        onSend(new Blob(chunksRef.current, { type: recorder.mimeType }), durationMs);
+      } else {
+        onCancel();
+      }
+    };
+    recorder.stop();
+  };
+
+  useEffect(() => {
+    let cancelled = false;
+    navigator.mediaDevices
+      .getUserMedia({ audio: true })
+      .then((stream) => {
+        if (cancelled) {
+          stream.getTracks().forEach((t) => t.stop());
+          return;
+        }
+        streamRef.current = stream;
+        const mimeType = AUDIO_MIME_TYPES.find((t) => MediaRecorder.isTypeSupported(t));
+        const recorder = new MediaRecorder(stream, mimeType ? { mimeType, audioBitsPerSecond: 24_000 } : undefined);
+        recorder.ondataavailable = (e) => {
+          if (e.data.size > 0) chunksRef.current.push(e.data);
+        };
+        recorder.start();
+        recorderRef.current = recorder;
+        startedAtRef.current = Date.now();
+        setReady(true);
+      })
+      .catch(() => setError('无法访问麦克风，请检查权限设置'));
+    return () => {
+      cancelled = true;
+      stopStream();
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
+  useEffect(() => {
+    if (!ready) return undefined;
+    const timer = window.setInterval(() => {
+      setSeconds((s) => {
+        const next = s + 1;
+        if (next * 1000 >= MAX_DURATION) finish(true);
+        return next;
+      });
+    }, 1000);
+    return () => window.clearInterval(timer);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [ready]);
+
+  if (error) {
+    return (
+      <div className="flex h-14 items-center justify-between rounded-lg bg-error-strip-bg px-4 text-sm text-error-strip-text">
+        {error}
+        <button type="button" onClick={onCancel} className="text-accent">
+          知道了
+        </button>
+      </div>
+    );
+  }
+
+  return (
+    <div className="flex h-14 items-center justify-between rounded-lg bg-[#fff0f0] px-4">
+      <span className="flex items-center gap-2 text-sm font-medium text-danger-text">
+        <span className="h-2.5 w-2.5 animate-pulse rounded-full bg-danger-text" />
+        录音中 {formatSeconds(seconds)}
+      </span>
+      <div className="flex items-center gap-4">
+        <button type="button" onClick={() => finish(false)} className="text-sm text-text-secondary">
+          取消
+        </button>
+        <button
+          type="button"
+          onClick={() => finish(true)}
+          disabled={!ready}
+          className="flex h-8 items-center gap-1 rounded-lg bg-btn px-4 text-sm font-medium text-white shadow-btn disabled:bg-btn-disabled"
+        >
+          <Icon name="send" className="text-[16px]" />
+          发送
+        </button>
+      </div>
+    </div>
+  );
+}