feat(desktop): port v0.11.4-v0.15.2 from Tauri to Electron + Discord-parity audio (v0.16.0)

Chronological port of every Tauri release commit (v0.11.4 -> v0.15.2)
into the Electron rebuild, plus Discord-style audio handling that goes
beyond the Tauri original.

Highlights:
  - All 17 Tauri release commits ported (audio fixes, custom notification
    sound, Discord-style chat UX, profile banner, changelog page,
    Discord-parity call UX, screen-share echo + re-watch UX, audio-loop
    fix).
  - Native napi-rs audio-loopback addon with WASAPI process-loopback:
      * EXCLUDE_TARGET_PROCESS_TREE for full-screen shares -> peers
        never hear themselves echoed back through the capture.
      * INCLUDE_TARGET_PROCESS_TREE for window shares -> only the
        picked window's audio is captured, not the whole OS mixer
        (Discord parity).
      * HWND -> PID resolution via Win32 GetWindowThreadProcessId.
  - Discord-style screen-source picker (thumbnail grid, screens vs
    apps tabs, live-refreshing thumbnails).
  - Hash routing fix for packaged builds (file:// can't resolve
    BrowserRouter paths).
  - Tauri sources removed (apps/desktop/src-tauri).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/desktop/src/components/IncomingCallPanel.tsx

@@ -1,8 +1,10 @@
 import type { ConversationSummary } from '@chat-app/shared/chat';
+import { useState } from 'react';
 import { useTranslation } from 'react-i18next';
 
 import { useCall } from '../context/CallContext';
 import { useFriendshipsContext } from '../context/FriendshipsContext';
+import { CallPreviewModal } from './CallPreviewModal';
 import { AvatarColorKey, colorKeyFor } from './CallParticipantTile';
 import { LockIcon, PhoneIcon, PhoneOffIcon, VideoIcon } from './icons';
 
@@ -24,6 +26,7 @@ export function IncomingCallPanel({ conversation }: Props) {
   const { t } = useTranslation(['app']);
   const { state, acceptIncoming, rejectIncoming } = useCall();
   const { friendships } = useFriendshipsContext();
+  const [showPreview, setShowPreview] = useState(false);
 
   if (state.kind !== 'incoming' || state.conversationId !== conversation.id) return null;
 
@@ -56,13 +59,15 @@ export function IncomingCallPanel({ conversation }: Props) {
           {t('app:call.incoming_title')}
         </p>
         <div className="relative my-4 flex h-[112px] w-[112px] items-center justify-center">
+          {/* Discord-style: animated pulse rings when motion is OK; one
+              static ring + a faint outer glow when prefers-reduced-motion. */}
           <span
             aria-hidden="true"
-            className="pointer-events-none absolute inset-0 rounded-full border-2 border-accent animate-pulse-ring"
+            className="pointer-events-none absolute inset-0 rounded-full border-2 border-accent motion-safe:animate-pulse-ring motion-reduce:opacity-70"
           />
           <span
             aria-hidden="true"
-            className="pointer-events-none absolute inset-0 rounded-full border-2 border-accent animate-pulse-ring"
+            className="pointer-events-none absolute inset-0 rounded-full border-2 border-accent motion-safe:animate-pulse-ring motion-reduce:hidden"
             style={{ animationDelay: '1s' }}
           />
           {avatarUrl ? (
@@ -123,7 +128,7 @@ export function IncomingCallPanel({ conversation }: Props) {
           {state.mediaKind === 'video' && (
             <button
               type="button"
-              onClick={() => void acceptIncoming('video')}
+              onClick={() => setShowPreview(true)}
               className="inline-flex flex-1 basis-[30%] cursor-pointer items-center justify-center gap-2 rounded-[14px] bg-accent px-4 py-3.5 text-sm font-semibold text-accent-fg shadow-accept-btn transition hover:brightness-110 focus:outline-none focus-visible:ring-2 focus-visible:ring-accent/50"
             >
               <VideoIcon className="h-4 w-4" />
@@ -132,6 +137,17 @@ export function IncomingCallPanel({ conversation }: Props) {
           )}
         </div>
       </div>
+
+      {showPreview && (
+        <CallPreviewModal
+          title={title}
+          onJoin={() => {
+            setShowPreview(false);
+            void acceptIncoming('video');
+          }}
+          onCancel={() => setShowPreview(false)}
+        />
+      )}
     </section>
   );
 }