feat(apple): transfer controls, progress fixes, and project config

- Sender progress: aggregate only in-flight receivers so the bar clears on
  completion and is order-independent ("Sending to N")
- Add Stop sharing and per-receiver Refuse (pending requests) on the sender
- Fix macOS: raise approval modal above the Share sheet; drive foreground
  state off NSApplication so background notifications fire
- Persist app identity (display name, category) and signing team via
  Info.plist / project.yml / gitignored Local.xcconfig

apple/.gitignore

@@ -6,6 +6,9 @@ VnidropCore/Sources/VnidropCore/Vnidrop.swift
 # Generated by XcodeGen from project.yml
 VniDrop.xcodeproj/
 
+# Per-developer signing (team id); Signing.xcconfig optionally includes it
+Local.xcconfig
+
 # SwiftPM / Xcode
 .build/
 .swiftpm/