Python code audit — AST analysis, bugs, complexity, no LLM

Send Python source code — get back a structured JSON audit: issues list (errors, warnings, info) with line numbers and codes; metrics (total lines, functions, classes, cyclomatic complexity); and a verdict. Checks for: bare except, eval/exec usage, mutable default arguments, global statements, TODO markers, long lines. Pure AST analysis — no LLM, no network, deterministic. Input: Python code string or JSON {code, filename}.