feat: add getPropertyCountAsync and getInstanceCountAsync and deprecate propertyCount and instanceCount (#198)

## Summary
- Add `getPropertyCountAsync()` and `getInstanceCountAsync()` async
methods to `ViewModel`
- Deprecate sync `propertyCount` and `instanceCount` properties — the
experimental Rive runtime requires async calls, and sync versions use
blocking wrappers that can deadlock on the main thread
- Legacy implementations wrap the existing sync getters in
`Promise.async`
- Update harness test to use async methods

## Test plan
- [x] Run `databinding-advanced` harness tests on iOS and Android

Author: mfazekas

android/src/main/java/com/margelo/nitro/rive/HybridViewModel.kt

@@ -53,6 +53,14 @@ class HybridViewModel(private val viewModel: ViewModel) : HybridViewModelSpec()
     }
   }
 
+  override fun getPropertyCountAsync(): Promise<Double> {
+    return Promise.async { propertyCount }
+  }
+
+  override fun getInstanceCountAsync(): Promise<Double> {
+    return Promise.async { instanceCount }
+  }
+
   override fun createInstanceByNameAsync(name: String): Promise<HybridViewModelInstanceSpec?> {
     return Promise.async { createInstanceByName(name) }
   }

example/__tests__/databinding-advanced.harness.ts

@@ -73,9 +73,8 @@ describe('ViewModel Properties Metadata', () => {
     const file = await loadFile(DATABINDING);
     const vm = file.viewModelByName('Person');
     expectDefined(vm);
-    // Legacy returns 8/2, experimental returns 0/0
-    expect(vm.propertyCount).toBeGreaterThanOrEqual(0);
-    expect(vm.instanceCount).toBeGreaterThanOrEqual(0);
+    expect(await vm.getPropertyCountAsync()).toBeGreaterThanOrEqual(0);
+    expect(await vm.getInstanceCountAsync()).toBeGreaterThanOrEqual(0);
   });
 });
 

ios/HybridViewModel.swift

@@ -41,6 +41,14 @@ class HybridViewModel: HybridViewModelSpec {
     return HybridViewModelInstance(viewModelInstance: vmi)
   }
 
+  func getPropertyCountAsync() throws -> Promise<Double> {
+    return Promise.async { self.propertyCount }
+  }
+
+  func getInstanceCountAsync() throws -> Promise<Double> {
+    return Promise.async { self.instanceCount }
+  }
+
   func createInstanceByNameAsync(name: String) throws -> Promise<(any HybridViewModelInstanceSpec)?> {
     return Promise.async { try self.createInstanceByName(name: name) }
   }