refactor(desktop): replace VoiceChannelRail with CallPreviewPanel

Drops the always-on 'Sprach-Channel' banner. The preview panel renders
only when peers are in the active call (1:1 and group identical).
Calls are still started via the topbar phone icon.

apps/desktop/src/components/VoiceChannelRail.tsx

@@ -1,141 +0,0 @@
-import type { ConversationSummary } from '@chat-app/shared/chat';
-import { useTranslation } from 'react-i18next';
-
-import { useAuth } from '../context/AuthContext';
-import { useCall } from '../context/CallContext';
-import { useCallPresence } from '../lib/useCallPresence';
-import { Avatar } from './Avatar';
-import { PhoneIcon, SpinnerIcon } from './icons';
-
-interface Props {
-  conversation: ConversationSummary;
-}
-
-const MAX_AVATARS = 5;
-
-/**
- * Discord-style persistent voice-channel band rendered at the top of the
- * message surface. Always visible for groups so any member can pop in
- * without an invite-ring; for 1:1 conversations only when someone's already
- * in (a soft "rejoin" affordance). Joining uses the existing joinActiveCall
- * path which sends no invite signals.
- */
-export function VoiceChannelRail({ conversation }: Props) {
-  const { t } = useTranslation(['app']);
-  const { session } = useAuth();
-  const { state, joinActiveCall } = useCall();
-  const presentIds = useCallPresence(conversation.id);
-
-  const myId = session?.user.id ?? null;
-  const iAmIn =
-    (state.kind === 'connected' ||
-      state.kind === 'connecting' ||
-      state.kind === 'reconnecting') &&
-    state.conversationId === conversation.id;
-
-  const others = presentIds.filter((u) => u !== myId);
-  const isGroup = conversation.type === 'group';
-
-  // For groups: persistent channel feel — show even when empty.
-  // For DMs: only when somebody is already in (matches Discord-DM behaviour).
-  const visible = !iAmIn && (isGroup || others.length > 0);
-  if (!visible) return null;
-
-  const showAvatars = others.slice(0, MAX_AVATARS);
-  const overflow = Math.max(0, others.length - MAX_AVATARS);
-  const busy = state.kind !== 'idle';
-
-  const handleJoin = () => {
-    if (busy) return;
-    void joinActiveCall(conversation.id, 'audio');
-  };
-
-  return (
-    <div
-      role="button"
-      tabIndex={0}
-      onClick={handleJoin}
-      onKeyDown={(e) => {
-        if (e.key === 'Enter' || e.key === ' ') {
-          e.preventDefault();
-          handleJoin();
-        }
-      }}
-      className={
-        'flex cursor-pointer items-center gap-3 border-b border-line px-5 py-2.5 text-sm transition focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/40 ' +
-        (others.length > 0
-          ? 'bg-emerald-500/10 hover:bg-emerald-500/15'
-          : 'bg-surface-3/70 hover:bg-surface-3')
-      }
-    >
-      <div
-        className={
-          'flex h-8 w-8 shrink-0 items-center justify-center rounded-md ' +
-          (others.length > 0 ? 'bg-emerald-500/20 text-emerald-500' : 'bg-accent/15 text-accent')
-        }
-      >
-        <PhoneIcon className="h-4 w-4" />
-      </div>
-      <div className="min-w-0 flex-1">
-        <p className="text-[11px] font-semibold uppercase tracking-[0.12em] text-fg-muted">
-          {t('app:call.voice_channel', { defaultValue: 'Sprach-Channel' })}
-        </p>
-        <p className="truncate text-xs text-fg">
-          {others.length === 0
-            ? t('app:call.voice_empty', {
-                defaultValue: 'Niemand drin — sei der Erste.',
-              })
-            : t('app:call.voice_count', {
-                defaultValue: '{{count}} im Channel',
-                count: others.length,
-              })}
-        </p>
-      </div>
-      {showAvatars.length > 0 && (
-        <div className="flex -space-x-2">
-          {showAvatars.map((id) => {
-            const member = conversation.members.find((m) => m.userId === id);
-            return (
-              <div
-                key={id}
-                title={member?.profile?.displayName ?? '?'}
-                className="relative h-7 w-7 overflow-hidden rounded-full border-2 border-surface-3 bg-surface-2"
-              >
-                <Avatar
-                  url={member?.profile?.avatarUrl ?? null}
-                  displayName={member?.profile?.displayName ?? '?'}
-                  className="h-full w-full text-[10px]"
-                />
-              </div>
-            );
-          })}
-          {overflow > 0 && (
-            <span className="inline-flex h-7 min-w-[1.75rem] items-center justify-center rounded-full border-2 border-surface-3 bg-surface-2 px-1.5 text-[10px] font-semibold text-fg-muted">
-              +{overflow}
-            </span>
-          )}
-        </div>
-      )}
-      <button
-        type="button"
-        onClick={(e) => {
-          e.stopPropagation();
-          handleJoin();
-        }}
-        disabled={busy}
-        className="inline-flex shrink-0 cursor-pointer items-center gap-1.5 rounded-md bg-emerald-600 px-3 py-1.5 text-xs font-semibold text-white transition hover:bg-emerald-500 focus:outline-none focus-visible:ring-2 focus-visible:ring-emerald-400/40 disabled:cursor-not-allowed disabled:opacity-60"
-      >
-        {busy ? (
-          <SpinnerIcon className="h-3.5 w-3.5" />
-        ) : (
-          <PhoneIcon className="h-3.5 w-3.5" />
-        )}
-        <span>
-          {others.length === 0
-            ? t('app:call.voice_open', { defaultValue: 'Channel öffnen' })
-            : t('app:call.join', { defaultValue: 'Beitreten' })}
-        </span>
-      </button>
-    </div>
-  );
-}

apps/desktop/src/pages/ConversationPage.tsx

@@ -23,7 +23,7 @@ import {
 } from '../components/icons';
 import { InCallPanel } from '../components/InCallPanel';
 import { IncomingCallPanel } from '../components/IncomingCallPanel';
-import { VoiceChannelRail } from '../components/VoiceChannelRail';
+import { CallPreviewPanel } from '../components/CallPreviewPanel';
 import { MediaFilesDrawer } from '../components/MediaFilesDrawer';
 import { MentionAutocomplete } from '../components/MentionAutocomplete';
 import { MessageBubble, type QuotedRef } from '../components/MessageBubble';
@@ -654,7 +654,7 @@ export function ConversationPage() {
           {/* Discord-style persistent voice-channel rail. Always visible in groups
               so anyone can pop in without an invite-ring; hidden in 1:1s unless
               someone is already waiting. Hides automatically once we're in. */}
-          {conversation && !incomingHere && <VoiceChannelRail conversation={conversation} />}
+          {conversation && !incomingHere && <CallPreviewPanel conversation={conversation} />}
           {incomingHere && conversation && <IncomingCallPanel conversation={conversation} />}
           {conversation && <InCallPanel conversation={conversation} />}