fix: line endings are now respected on windows

.changeset/clever-feet-move.md

@@ -0,0 +1,5 @@
+---
+"@manypkg/cli": minor
+---
+
+Respect line endings of package.json files on windows

packages/cli/src/utils.ts

@@ -7,11 +7,15 @@ import detectIndent from "detect-indent";
 export async function writePackage(pkg: Package) {
   let pkgRaw = await fs.readFile(path.join(pkg.dir, "package.json"), "utf-8");
   let indent = detectIndent(pkgRaw).indent || "  ";
-  return fs.writeFile(
-    path.join(pkg.dir, "package.json"),
-    JSON.stringify(pkg.packageJson, null, indent) +
-      (pkgRaw.endsWith("\n") ? "\n" : "")
-  );
+  // Determine original EOL style and whether there was a trailing newline
+  const eol = pkgRaw.includes("\r\n") ? "\r\n" : "\n";
+  // Stringify and then normalize EOLs to match the original file
+  let json = JSON.stringify(pkg.packageJson, null, indent);
+  json = eol !== "\n" ? json.replace(/\n/g, eol) : json;
+  if (pkgRaw.endsWith("\n") /* true for both LF and CRLF */) {
+    json += eol;
+  }
+  return fs.writeFile(path.join(pkg.dir, "package.json"), json);
 }
 
 export async function install(toolType: string, cwd: string) {