Function extract_module_info 

pub fn extract_module_info(
    path: &PathBuf,
    source: &str,
) -> PatternsResult<ModuleInfo>

Extract module information from source code.

Detects language from file extension, parses the source using tree-sitter, and extracts:

• Top-level function and class definitions
• Import statements (language-specific)
• Function call sites within function bodies