Fix nullable racFree call, improve getHandle safety, remove unused import

Author: Reef-7

sdk/runanywhere-flutter/packages/runanywhere/lib/native/dart_bridge_vad.dart

@@ -13,7 +13,6 @@ import 'package:ffi/ffi.dart';
 import 'package:runanywhere/foundation/logging/sdk_logger.dart';
 import 'package:runanywhere/native/ffi_types.dart';
 import 'package:runanywhere/native/native_functions.dart';
-import 'package:runanywhere/native/platform_loader.dart';
 
 /// VAD component bridge for C++ interop.
 ///
@@ -226,7 +225,12 @@ class DartBridgeVAD {
         samplesPtr[i] = samples[i];
       }
 
-      final status = NativeFunctions.vadProcess(handle, samplesPtr, samples.length, resultPtr);
+      final status = NativeFunctions.vadProcess(
+        handle,
+        samplesPtr,
+        samples.length,
+        resultPtr.cast<Void>(),
+      );
 
       if (status != RAC_SUCCESS) {
         throw StateError(

sdk/runanywhere-flutter/packages/runanywhere/lib/native/dart_bridge_voice_agent.dart

@@ -24,7 +24,7 @@ void _safeRacFree(Pointer<Void> ptr) {
   if (ptr == nullptr) return;
 
   try {
-    NativeFunctions.racFree(ptr);
+    NativeFunctions.racFree?.call(ptr);
   } catch (_) {
     // rac_free may not exist in some native builds
   }
@@ -73,10 +73,8 @@ class DartBridgeVoiceAgent {
       return _handle!;
     }
 
-    final initFuture = _initFuture;
-    if (initFuture != null) {
-      await initFuture;
-      return _handle!;
+    if (_initFuture != null) {
+      return _initFuture!;
     }
 
     final completer = Completer<RacHandle>();
@@ -618,10 +616,11 @@ final int Function(
   int,
   Pointer<RacVoiceAgentResultStruct>,
 ) _processVoiceTurnFn = _voiceAgentLib.lookupFunction<
-    Int32 Function(RacHandle, Pointer<Void>, IntPtr,
-        Pointer<RacVoiceAgentResultStruct>),
-    int Function(RacHandle, Pointer<Void>, int,
-        Pointer<RacVoiceAgentResultStruct>)>('rac_voice_agent_process_voice_turn');
+        Int32 Function(RacHandle, Pointer<Void>, IntPtr,
+            Pointer<RacVoiceAgentResultStruct>),
+        int Function(
+            RacHandle, Pointer<Void>, int, Pointer<RacVoiceAgentResultStruct>)>(
+    'rac_voice_agent_process_voice_turn');
 
 final void Function(Pointer<RacVoiceAgentResultStruct>)?
     _voiceAgentResultFreeFn = (() {