fix(whatsapp): keep QR login state in sync

Keep WhatsApp QR login state synced across gateway, macOS, and UI wait flows.

- Preserve the latest QR data URL/version while login polling rotates codes.
- Keep the wait-result protocol bounded to current QR metadata.
- Stabilize QR rendering and media fixture coverage after rebasing on main.

Validation:
- pnpm test extensions/whatsapp/src/login-qr.test.ts extensions/whatsapp/src/media.test.ts extensions/whatsapp/src/agent-tools-login.test.ts src/gateway/protocol/channels.schema.test.ts src/gateway/server-methods/web.start.test.ts ui/src/ui/controllers/channels.test.ts
- pnpm test:extension whatsapp
- cd apps/macos && swift test --filter ChannelsSettingsSmokeTests
- GitHub PR checks: 62 success, 5 skipped

src/channels/plugins/types.adapters.ts

@@ -324,6 +324,7 @@ export type ChannelLoginWithQrStartResult = {
 export type ChannelLoginWithQrWaitResult = {
   connected: boolean;
   message: string;
+  qrDataUrl?: string;
 };
 
 export type ChannelLogoutContext<ResolvedAccount = unknown> = {
@@ -348,6 +349,7 @@ export type ChannelGatewayAdapter<ResolvedAccount = unknown> = {
   loginWithQrWait?: (params: {
     accountId?: string;
     timeoutMs?: number;
+    currentQrDataUrl?: string;
   }) => Promise<ChannelLoginWithQrWaitResult>;
   logoutAccount?: (ctx: ChannelLogoutContext<ResolvedAccount>) => Promise<ChannelLogoutResult>;
 };