fix: refine linux voice runtime behavior

apps/chanora_flutter/lib/src/rust/api.dart

@@ -198,7 +198,8 @@ Future<void> sendChatMessage({
 /// On non-Android targets or before a voice session opens the
 /// section is omitted. Per SDD-090 every field in that section is
 /// a device-side technical scalar — no PII admitted.
-String exportDiagnostics() => RustLib.instance.api.crateApiExportDiagnostics();
+Future<String> exportDiagnostics() =>
+    RustLib.instance.api.crateApiExportDiagnostics();
 
 /// Wire the identity persistence store to a platform-private
 /// directory. Should be called once on app start after Flutter has

apps/chanora_flutter/lib/src/rust/frb_generated.dart

@@ -101,7 +101,7 @@ abstract class RustLibApi extends BaseApi {
 
   Stream<BridgeEvent> crateApiEventsStream();
 
-  String crateApiExportDiagnostics();
+  Future<String> crateApiExportDiagnostics();
 
   Future<BridgeAudioProcessingConfig> crateApiGetAudioProcessingConfig();
 
@@ -469,16 +469,21 @@ class RustLibApiImpl extends RustLibApiImplPlatform implements RustLibApi {
       const TaskConstMeta(debugName: "events_stream", argNames: ["sink"]);
 
   @override
-  String crateApiExportDiagnostics() {
-    return handler.executeSync(
-      SyncTask(
-        callFfi: () {
+  Future<String> crateApiExportDiagnostics() {
+    return handler.executeNormal(
+      NormalTask(
+        callFfi: (port_) {
           final serializer = SseSerializer(generalizedFrbRustBinding);
-          return pdeCallFfi(generalizedFrbRustBinding, serializer, funcId: 10)!;
+          pdeCallFfi(
+            generalizedFrbRustBinding,
+            serializer,
+            funcId: 10,
+            port: port_,
+          );
         },
         codec: SseCodec(
           decodeSuccessData: sse_decode_String,
-          decodeErrorData: null,
+          decodeErrorData: sse_decode_bridge_error,
         ),
         constMeta: kCrateApiExportDiagnosticsConstMeta,
         argValues: [],