Fix Windows path handling in module-details-from-path

On Windows, module-details-from-path only works with backslash-separated
paths. Bundlers (esbuild, vite, rollup) normalize paths to forward slashes
on all platforms, causing module-details-from-path to return null on Windows.

This fix normalizes bundler paths to use the platform-native separator
before passing to module-details-from-path, ensuring it works correctly
on Windows.

Fixes path matching issues that prevented instrumentation on Windows builds.

Author: Qard

src/plugin.ts

@@ -53,7 +53,11 @@ const unplugin = createUnplugin<CodeTransformerPluginOptions>((options) => {
             }
 
             // Try to get module details from the file path
-            const moduleDetails = moduleDetailsFromPath(id);
+            // IMPORTANT: On Windows, module-details-from-path only works with backslash paths.
+            // Bundlers typically normalize to forward slashes, so we convert back to the
+            // platform-native separator.
+            const normalizedId = process.platform === 'win32' ? id.replace(/\//g, '\\') : id;
+            const moduleDetails = moduleDetailsFromPath(normalizedId);
 
             // If no module details found, the file is not part of a module
             if (!moduleDetails) {