Rename app from RustDesk to SoonDesk

Changes:
- libs/hbb_common/src/config.rs: APP_NAME = 'SoonDesk' (single source of truth)
- flutter/lib/desktop/widgets/tabbar_widget.dart: hard-coded tab title
- flutter/macos/Runner/Configs/AppInfo.xcconfig: PRODUCT_NAME, BUNDLE_ID
- flutter/macos/Runner.xcodeproj/project.pbxproj: hard-coded BUNDLE_ID override
- flutter/lib/web/bridge.dart: comment about why isCustomClient comparison unchanged

This single APP_NAME change drives:
- Window title (src/ui.rs:87 frame.set_title(&crate::get_app_name()))
- macOS app bundle display name (CFBundleName via $(PRODUCT_NAME))
- Linux .desktop file name
- Config / log directory paths (~/Library/Logs/SoonDesk/)
- Lang translation strings: src/lang.rs auto-replaces 'RustDesk' in all
  translations with APP_NAME when is_rustdesk() returns false (since
  APP_NAME is no longer 'RustDesk').

Protocol-level 'RustDesk' references are preserved (PunchHoleRequest
fields, etc.) so we still interop with upstream RustDesk servers and
clients.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

flutter/macos/Runner/Configs/AppInfo.xcconfig

@@ -5,10 +5,10 @@
 // 'flutter create' template.
 
 // The application's name. By default this is also the title of the Flutter window.
-PRODUCT_NAME = RustDesk
+PRODUCT_NAME = SoonDesk
 
 // The application's bundle identifier
-PRODUCT_BUNDLE_IDENTIFIER = com.carriez.flutterHbb
+PRODUCT_BUNDLE_IDENTIFIER = com.cardsoon.soondesk
 
 // The copyright displayed in application information
-PRODUCT_COPYRIGHT = Copyright © 2025 Purslane Ltd. All rights reserved.
+PRODUCT_COPYRIGHT = Copyright © 2026 Cardsoon. All rights reserved.