fix(models): fix method variable scope in quantization fallback

The method variable was declared inside the for loop, causing
'method is not defined' error when referenced after the loop.
Moved declaration outside loop to fix scope issue.

This allows the FP32 fallback to work correctly when INT4
quantization fails (e.g., on incompatible model architectures).

Author: jdalton

packages/models/scripts/build.mjs

@@ -212,6 +212,7 @@ async function quantizeModel(modelKey) {
     : [{ input: 'model.onnx', output: 'model.int4.onnx' }]
 
   const quantizedPaths = []
+  let method = 'INT4'
 
   for (const { input, output } of models) {
     const onnxPath = join(modelDir, input)
@@ -224,7 +225,6 @@ async function quantizeModel(modelKey) {
 
     let originalSize
     let quantSize
-    let method = 'INT4'
 
     try {
       await execAsync(