feat(web): real chat list + P2P conversation view against live Tinode data

Phase 2 core loop: chat list and single-chat conversation now read/write real
Tinode topic data end to end, replacing the earlier hardcoded placeholders.

- lib/tinode/topics.ts: per-topic pub-sub layered on connection.ts's pattern
  (Topic.onData/onInfo/etc are single-slot callbacks, claimed once and fanned
  out). Implements the old app's subscribe lifecycle: `me` subscribed once
  per session (metadata only), each contact gets a one-shot preview
  subscription (withLaterData(1), never left), opening a conversation
  leaves-then-resubscribes with a full history page (withData, not
  withLaterData -- a preview prefetch already nudging _maxSeq would make
  withLaterData return empty).
- lib/tinode/hooks.ts: useChatList()/useTopicMessages() via
  useSyncExternalStore, snapshots cached and only invalidated on real
  topic-change notifications (not recomputed every render).
- lib/tinode/send.ts: sendText/retryMessage via createMessage+publishDraft
  (optimistic local echo), not the simpler publish() -- matches the old
  app's approach. retryMessage flushes the failed local entry and rebuilds
  before republishing, per the old app's context-menu retry handler.
- lib/messages/{time,avatar,attachments,status,preview,dispatch,drafty}:
  formatting utilities. Avatar color hash ports the old app's Java-style
  string hash but with modulus 11 (this design's palette) not the old app's
  16. @mention renders flat accent blue per the new design, not the old
  app's per-user hash color -- a deliberate simplification. File-type icons
  (PDF/Word/Excel/PPT) are new-design-only; the old app buckets all
  documents identically. Date/time formatting is written fresh against the
  design spec (today+time combined, weekday tier) since the old app never
  combines a relative-date word with a time in one string.
- ChatListColumn, MessageBubble, ConversationView: real components replacing
  the placeholder chat list and "占位" conversation view.
- tinode-sdk.d.ts: expanded with the real Topic/MetaGetBuilder/Drafty
  surface needed above, verified against the installed SDK source
  (createMessage/publishDraft/messages/msgStatus/noteRead/flushMessage/
  Drafty.format's exact treeBottomUp contract, MESSAGE_STATUS_* statics).

Verified end to end against the real backend: used the still-functional old
app (a second account, ixp355087) to create a real friendship and exchange
messages with the new app's test account, confirming the new chat list and
conversation view correctly render pre-existing real data, sending a new
message shows the right optimistic-then-delivered status transition, and
the old app receives it live in return.

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

web/src/features/messages/ConversationView.tsx

@@ -1,36 +1,141 @@
+import { useEffect, useRef, useState } from 'react';
+
 import { Link, useOutletContext, useParams } from 'react-router-dom';
 
 import { Icon } from '@/app/Icon';
+import { MessageRow } from '@/features/messages/MessageBubble';
+import { avatarBgClass, avatarLetter } from '@/lib/avatar';
+import { useChatList, useTinode, useTopicMessages } from '@/lib/tinode/hooks';
+import { sendText } from '@/lib/tinode/send';
+import { closeConversation, openConversation } from '@/lib/tinode/topics';
+import { useSessionStore } from '@/stores/session';
 
 interface OutletCtx {
   onToggleDetail: () => void;
 }
 
-/** Placeholder chat surface -- real header/bubbles/composer land in Phase 1. */
 export function ConversationView() {
   const { topicId } = useParams();
   const { onToggleDetail } = useOutletContext<OutletCtx>();
+  const myUserId = useSessionStore((s) => s.myUserId);
+  const tinode = useTinode();
+  const contacts = useChatList();
+  const contact = contacts.find((c) => c.topic === topicId);
+  const messages = useTopicMessages(topicId);
+  const [draft, setDraft] = useState('');
+  const streamRef = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    if (!topicId) return undefined;
+    openConversation(topicId).catch(() => {});
+    return () => closeConversation(topicId);
+  }, [topicId]);
+
+  useEffect(() => {
+    streamRef.current?.scrollTo({ top: streamRef.current.scrollHeight });
+  }, [messages.length]);
+
+  useEffect(() => {
+    if (!topicId || messages.length === 0) return;
+    tinode.getTopic(topicId).noteRead(0);
+  }, [topicId, messages.length, tinode]);
+
+  if (!topicId) return null;
+  const topic = tinode.getTopic(topicId);
+  const peerName = contact?.public?.fn || topicId;
+  const isGroup = topic.isGroupType();
+
+  const submit = () => {
+    const text = draft.trim();
+    if (!text) return;
+    setDraft('');
+    sendText(topic, text);
+  };
+
+  const handleKeyDown = (e: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    if (e.key !== 'Enter' || e.shiftKey) return;
+    // Guards against CJK IME candidate-selection Enter keystrokes being mistaken for submit --
+    // a real, unfixed bug class in the old app (confirmed by its own research: zero isComposing/
+    // compositionstart/keyCode-229 guards anywhere in that codebase).
+    if (e.nativeEvent.isComposing) return;
+    e.preventDefault();
+    submit();
+  };
 
   return (
     <div className="flex h-full w-full flex-col bg-surface-chat">
       <header className="flex h-15 flex-none items-center justify-between border-b border-border-panel bg-white px-5">
-        <div className="flex items-center gap-2">
-          {/* Only the <960 tiers hide the list column, so only there do we need our own way back. */}
-          <Link to="/messages" className="grid h-9.5 w-9.5 place-items-center text-text-heading md:hidden">
+        <div className="flex items-center gap-2.5">
+          <Link to="/messages" className="grid h-9.5 w-9.5 flex-none place-items-center text-text-heading md:hidden">
             <Icon name="arrow_back_ios_new" />
           </Link>
-          <strong className="text-base font-semibold text-text-heading">{topicId}</strong>
+          <span className={`grid h-9.5 w-9.5 flex-none place-items-center rounded-lg text-sm font-medium text-white ${avatarBgClass(topicId)}`}>
+            {avatarLetter(peerName)}
+          </span>
+          <div className="flex flex-col">
+            <strong className="text-base font-semibold text-text-heading">{peerName}</strong>
+            <span className={`text-xs ${contact?.online ? 'text-online' : 'text-text-tertiary-2'}`}>{contact?.online ? '在线' : '离线'}</span>
+          </div>
+        </div>
+        <div className="flex items-center gap-1">
+          <button type="button" className="grid h-9.5 w-9.5 place-items-center rounded-lg text-text-tertiary-1">
+            <Icon name="call" />
+          </button>
+          <button type="button" className="grid h-9.5 w-9.5 place-items-center rounded-lg text-text-tertiary-1">
+            <Icon name="videocam" />
+          </button>
+          <button type="button" className="grid h-9.5 w-9.5 place-items-center rounded-lg text-text-tertiary-1">
+            <Icon name="search" />
+          </button>
+          <button
+            type="button"
+            onClick={onToggleDetail}
+            className="grid h-9.5 w-9.5 place-items-center rounded-lg text-text-tertiary-1 md:bg-accent-soft-bg md:text-accent lg:bg-transparent lg:text-text-tertiary-1"
+          >
+            <Icon name="info" />
+          </button>
         </div>
-        <button
-          type="button"
-          onClick={onToggleDetail}
-          className="grid h-9.5 w-9.5 place-items-center rounded-lg text-text-tertiary-1 md:bg-accent-soft-bg md:text-accent lg:bg-transparent lg:text-text-tertiary-1"
-        >
-          <Icon name="info" />
-        </button>
       </header>
-      <div className="flex flex-1 items-center justify-center text-sm text-text-tertiary-4">
-        消息流占位（阶段1实现）
+
+      <div ref={streamRef} className="flex flex-1 flex-col gap-4 overflow-y-auto px-7 py-5">
+        {messages.map((msg) => (
+          <MessageRow
+            key={msg.seq}
+            topic={topic}
+            msg={msg}
+            mine={!!myUserId && msg.from === myUserId}
+            isGroup={isGroup}
+            peerName={peerName}
+          />
+        ))}
+      </div>
+
+      <div className="flex-none border-t border-border-panel bg-white px-4 pb-3 pt-2">
+        <div className="flex items-center gap-1 px-1 pb-1">
+          <Icon name="sentiment_satisfied_alt" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
+          <Icon name="image" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
+          <Icon name="attach_file" className="grid h-8.5 w-8.5 place-items-center rounded text-[22px] text-icon-default" />
+          <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"
+          >
+            发送
+          </button>
+        </div>
       </div>
     </div>
   );