`SN006` Use tree-sitter for code scanning¶

Code scanning shall use tree-sitter to parse source files into an AST, extracting comment nodes and correlating them with the symbol they document.

This avoids custom parsing logic and correctly handles language-specific constructs such as Python docstrings, Rust doc comments (///), and C preprocessor directives.

Each supported language requires its corresponding tree-sitter grammar package (tree-sitter-python, tree-sitter-go, tree-sitter-rust).