fix: use UTF-8 for text file operations

skills/agent-builder/references/tool-templates.py

@@ -190,7 +190,7 @@ def run_read_file(path: str, limit: int = None) -> str:
     - Output truncated to 50KB
     """
     try:
-        text = safe_path(path).read_text()
+        text = safe_path(path).read_text(encoding="utf-8")
         lines = text.splitlines()
 
         if limit and limit < len(lines):
@@ -215,7 +215,7 @@ def run_write_file(path: str, content: str) -> str:
     try:
         fp = safe_path(path)
         fp.parent.mkdir(parents=True, exist_ok=True)
-        fp.write_text(content)
+        fp.write_text(content, encoding="utf-8")
         return f"Wrote {len(content)} bytes to {path}"
 
     except Exception as e:
@@ -233,13 +233,13 @@ def run_edit_file(path: str, old_text: str, new_text: str) -> str:
     """
     try:
         fp = safe_path(path)
-        content = fp.read_text()
+        content = fp.read_text(encoding="utf-8")
 
         if old_text not in content:
             return f"Error: Text not found in {path}"
 
         new_content = content.replace(old_text, new_text, 1)
-        fp.write_text(new_content)
+        fp.write_text(new_content, encoding="utf-8")
         return f"Edited {path}"
 
     except Exception as e: