Add BrassCoders — deterministic local pre-merge gate for AI-generated Python

[CopperSunDev]

What is BrassCoders?

BrassCoders is a deterministic, local, free pre-merge CLI that orchestrates 12 static-analysis scanners and emits ranked findings as YAML for AI coding assistants. Apache 2.0, distributed via PyPI as brasscoders, requires Python 3.10+.

Scanners bundled: Bandit, Pylint, Pyre/Pysa (taint), Semgrep, ast-grep, detect-secrets (Yelp), plus six custom scanners for performance anti-patterns, secrets, PII, AI-pattern detection, content moderation, and JavaScript/TypeScript.

The distinctive coverage: four AST-level rules that catch the performance anti-patterns AI coding assistants reliably introduce — O(N²) string concatenation in loops, list.insert(0) in loops, N-deep nested loops used as joins, and unbounded while True polls — which Bandit, Pylint, and Semgrep have no rules for.

Reproducibility: same scan on same code produces identical output every run. Designed as a CI gate (brasscoders --offline scan), not an advisory tool.

• Source: https://github.com/CopperSunDev/brasscoders
• PyPI: https://pypi.org/project/brasscoders/
• License: Apache-2.0
• Homepage: https://coppersun.dev

Benchmark data (12 AI-generated Python files, one planted bug each): BrassCoders 11/12, Bandit 6/12, Pylint 1/12, frontier model 12/12. Wedge: BrassCoders 4/4 on AI-coder perf anti-patterns; all others 0/4.