Potential fix for code scanning alert no. 106: Incomplete string escaping or encoding

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

Author: dgca

packages/create-onchain/scripts/copy-templates.js

@@ -106,6 +106,7 @@ function shouldIgnoreFile(filePath, gitignoreRules) {
     if (rule.includes('*')) {
       // Handle simple wildcards - convert to proper regex
       let pattern = rule
+        .replace(/\\/g, '\\\\') // Escape backslashes
         .replace(/\./g, '\\.')  // Escape dots
         .replace(/\?/g, '.')    // ? matches one character
         .replace(/\*/g, '[^/]*'); // * matches any characters except /