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>

packages/shared/src/chat/attachments.ts

@@ -53,7 +53,20 @@ export interface CallEventPayload {
   durationSec: number;
 }
 
-export type MessagePayload = TextMessagePayload | CallEventPayload;
+export interface PollOption {
+  id: string;
+  emoji: string;
+  text: string;
+}
+
+export interface PollPayload {
+  v: 1;
+  type: 'poll';
+  question: string;
+  options: PollOption[];
+}
+
+export type MessagePayload = TextMessagePayload | CallEventPayload | PollPayload;
 
 export type ParsedMessagePayload =
   | {
@@ -67,6 +80,11 @@ export type ParsedMessagePayload =
       status: CallEventStatus;
       mediaKind: CallEventKind;
       durationSec: number;
+    }
+  | {
+      kind: 'poll';
+      question: string;
+      options: PollOption[];
     };
 
 export function serializeMessagePayload(payload: MessagePayload): string {
@@ -95,6 +113,34 @@ export function parseMessagePayload(raw: string | null): ParsedMessagePayload {
           durationSec: typeof p.durationSec === 'number' ? p.durationSec : 0,
         };
       }
+      if (obj.type === 'poll') {
+        const p = obj as Partial<PollPayload>;
+        const options = Array.isArray(p.options)
+          ? p.options
+              .map((option, idx) => {
+                const candidate = option as Partial<PollOption>;
+                const text = typeof candidate.text === 'string' ? candidate.text.trim() : '';
+                if (!text) return null;
+                return {
+                  id:
+                    typeof candidate.id === 'string' && candidate.id.trim()
+                      ? candidate.id.trim()
+                      : 'option-' + (idx + 1),
+                  emoji:
+                    typeof candidate.emoji === 'string' && candidate.emoji.trim()
+                      ? candidate.emoji.trim()
+                      : String(idx + 1),
+                  text,
+                };
+              })
+              .filter((option): option is PollOption => option !== null)
+          : [];
+        return {
+          kind: 'poll',
+          question: typeof p.question === 'string' ? p.question.trim() : '',
+          options,
+        };
+      }
       const t = obj as TextMessagePayload;
       return {
         kind: 'text',