fix: add utf-8 encoding to JS line profiler read/write, scope encoding rule

Author: KRRT7

.claude/rules/code-style.md

@@ -8,4 +8,4 @@
 - **Docstrings**: Do not add unless explicitly requested
 - **Naming**: NEVER use leading underscores (`_function_name`) - Python has no true private functions, use public names
 - **Paths**: Always use absolute paths
-- **Encoding**: Always pass `encoding="utf-8"` to `open()`, `read_text()`, `write_text()`, etc. — Windows defaults to `cp1252` which breaks on non-ASCII content
+- **Encoding**: Always pass `encoding="utf-8"` to `open()`, `read_text()`, `write_text()`, etc. in new or changed code — Windows defaults to `cp1252` which breaks on non-ASCII content. Don't flag pre-existing code that lacks it unless you're already modifying that line.

codeflash/languages/javascript/function_optimizer.py

@@ -175,7 +175,7 @@ def line_profiler_step(
             logger.warning(f"Language support for {self.language_support.language} doesn't support line profiling")
             return {"timings": {}, "unit": 0, "str_out": ""}
 
-        original_source = Path(self.function_to_optimize.file_path).read_text()
+        original_source = self.function_to_optimize.file_path.read_text(encoding="utf-8")
         try:
             line_profiler_output_path = get_run_tmp_file(Path("line_profiler_output.json"))
 
@@ -205,7 +205,7 @@ def line_profiler_step(
             logger.warning(f"Failed to run line profiling: {e}")
             return {"timings": {}, "unit": 0, "str_out": ""}
         finally:
-            Path(self.function_to_optimize.file_path).write_text(original_source)
+            self.function_to_optimize.file_path.write_text(original_source, encoding="utf-8")
 
     def replace_function_and_helpers_with_optimized_code(
         self,