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/lib/conversationFeatures.test.ts

@@ -0,0 +1,97 @@
+import {
+  parseMessagePayload,
+  type AttachmentHandle,
+  type DecryptedMessage,
+} from '@chat-app/shared/chat';
+import { describe, expect, it } from 'vitest';
+
+import {
+  collectConversationAttachments,
+  createPollPayload,
+  summarizePollVotes,
+} from './conversationFeatures';
+
+function handle(id: string, mimeType: string): AttachmentHandle {
+  return {
+    id,
+    storagePath: 'conversation/' + id + '.bin',
+    mimeType,
+    sizeBytes: 2048,
+    keyB64: 'key',
+    nonceB64: 'nonce',
+  };
+}
+
+function message(id: string, createdAt: string, attachments: AttachmentHandle[]): DecryptedMessage {
+  return {
+    id,
+    conversationId: 'conv-1',
+    senderId: 'sender-1',
+    senderDeviceId: 'device-1',
+    replyToId: null,
+    editedAt: null,
+    deletedAt: null,
+    createdAt,
+    plaintext: JSON.stringify({ v: 1, type: 'text', text: '', attachments }),
+  };
+}
+
+describe('collectConversationAttachments', () => {
+  it('indexes media, audio, and files newest first', () => {
+    const first = message('m1', '2026-04-24T09:00:00.000Z', [
+      handle('img-1', 'image/png'),
+      handle('file-1', 'application/pdf'),
+    ]);
+    const second = message('m2', '2026-04-24T10:00:00.000Z', [
+      handle('audio-1', 'audio/webm'),
+      handle('video-1', 'video/mp4'),
+    ]);
+
+    const index = collectConversationAttachments([first, second]);
+
+    expect(index.media.map((item) => item.handle.id)).toEqual(['video-1', 'img-1']);
+    expect(index.audio.map((item) => item.handle.id)).toEqual(['audio-1']);
+    expect(index.files.map((item) => item.handle.id)).toEqual(['file-1']);
+    expect(index.all.map((item) => item.messageId)).toEqual(['m2', 'm2', 'm1', 'm1']);
+  });
+});
+
+describe('createPollPayload', () => {
+  it('creates a parseable encrypted-message poll payload', () => {
+    const payload = createPollPayload('  Lieblings Feature?  ', [' Media Drawer ', '', 'Polls']);
+    const parsed = parseMessagePayload(payload);
+
+    expect(parsed.kind).toBe('poll');
+    if (parsed.kind !== 'poll') throw new Error('expected poll payload');
+    expect(parsed.question).toBe('Lieblings Feature?');
+    expect(parsed.options).toEqual([
+      { id: 'option-1', emoji: '1️⃣', text: 'Media Drawer' },
+      { id: 'option-2', emoji: '2️⃣', text: 'Polls' },
+    ]);
+  });
+
+  it('requires a question and at least two non-empty options', () => {
+    expect(() => createPollPayload('', ['A', 'B'])).toThrow('question');
+    expect(() => createPollPayload('Feature?', ['A', ''])).toThrow('options');
+  });
+});
+
+describe('summarizePollVotes', () => {
+  it('counts only configured poll options and marks the current user vote', () => {
+    const summary = summarizePollVotes(
+      [
+        { id: 'option-1', emoji: '1️⃣', text: 'Media Drawer' },
+        { id: 'option-2', emoji: '2️⃣', text: 'Polls' },
+      ],
+      [
+        { emoji: '1️⃣', count: 3, mine: false },
+        { emoji: '2️⃣', count: 1, mine: true },
+        { emoji: '🔥', count: 99, mine: true },
+      ],
+    );
+
+    expect(summary.totalVotes).toBe(4);
+    expect(summary.options.map((option) => option.percent)).toEqual([75, 25]);
+    expect(summary.options.map((option) => option.mine)).toEqual([false, true]);
+  });
+});