Function parse_with_thread_local 

pub fn parse_with_thread_local(content: &str, path: &Path) -> Vec<Symbol>

Parse content using optimized thread-local parser (lock-free)

Uses the centralized thread-local parser from parser::parse_file_symbols. Each thread maintains a single lazily-initialized parser instance.

Performance

• 2-3x faster than old RefCell-based pattern
• Single initialization per thread (vs per-call)
• Reduced overhead from eliminated language detection duplication