Fix tests with sync WASM loading

reconcile-js/__mocks__/wasm.js

@@ -0,0 +1,9 @@
+const fs = require('fs');
+const path = require('path');
+
+// Read the actual WASM file and convert to base64 for testing
+const wasmPath = path.join(__dirname, '../../pkg/reconcile_bg.wasm');
+const wasmBuffer = fs.readFileSync(wasmPath);
+const wasmBase64 = wasmBuffer.toString('base64');
+
+module.exports = wasmBase64;