fix: enable macOS framework linking by setting ObjC language mode

native_toolchain_c only passes -framework flags to clang when the
language is objectiveC. Without this, IOKit/CoreFoundation/AppKit
frameworks were silently dropped, causing undefined symbol errors on
macOS. Also fix hidOpen test to use 0xFFFF/0xFFFF instead of 0/0,
since VID/PID 0 is a wildcard that matches real devices on macOS.

Author: repentsinner

hook/build.dart

@@ -37,6 +37,9 @@ void main(List<String> args) async {
         if (targetOS == OS.linux) '$sourcePath/linux/hid.c',
       ],
       includes: ['$sourcePath/hidapi'],
+      // native_toolchain_c only passes -framework flags when
+      // language is set to objectiveC — plain C silently drops them.
+      language: targetOS == OS.macOS ? Language.objectiveC : Language.c,
       frameworks: [
         if (targetOS == OS.macOS) 'IOKit',
         if (targetOS == OS.macOS) 'CoreFoundation',

test/hidapi_test.dart

@@ -78,10 +78,13 @@ void main() {
       }
     });
 
-    test('hidOpen throws HidException for invalid VID/PID', () {
+    test('hidOpen with VID/PID 0xFFFF/0xFFFF throws HidException', () {
       hidInit();
       try {
-        expect(() => hidOpen(0, 0), throwsA(isA<HidException>()));
+        expect(
+          () => hidOpen(0xFFFF, 0xFFFF),
+          throwsA(isA<HidException>()),
+        );
       } finally {
         hidExit();
       }