feat(script): Apply framework ruff ignores to subdirectories, scoped to them

[jpmckinney]

tests/script.sh detects frameworks only from the root requirements.txt or pyproject.toml. When a repository's root is not Django but a subdirectory is (e.g. a Django app in prototype/ with its own pyproject.toml), the app is linted as plain Python. It then reports PT009, DJ008, RUF012 and similar findings that Django repositories normally ignore.

This PR moves the framework checks into a function, add_framework_ignores FILE PREFIX, and also calls it for each subdirectory with a tracked requirements.txt or pyproject.toml (skipping docs/, which is for Read the Docs). For the root, behaviour is unchanged. For a subdirectory, rules are added as per-file ignores (prototype/*:PT) and patterns are prefixed (prototype/*/views.py:ARG001), so a non-Django root does not have PT, DJ008 or S308 ignored repository-wide. Glob metacharacters in the directory name are escaped, so cookiecutter directories like {{cookiecutter.project_slug}} match.

Tested:

• A private repository with a Django app in a subdirectory: PT009 71 -> 0, PT027 2 -> 0, DJ008 6 -> 0, RUF012 11 -> 1. Other rules are unchanged.
• data-registry, credere-backend, standard-maintenance-scripts: the generated ruff arguments are identical before and after.
• software-development-handbook: only adds Django ignores scoped to the cookiecutter directory, and 'id'.
• The ruff glob behaviour (root-anchored patterns, * crossing /, escaping {{…}}) was checked with ruff 0.16.8. The script passes shellcheck and behaves the same under macOS's /bin/bash 3.2.

Limitations:

• The builtins ignorelist can't be set per file, so 'id' from a Django subdirectory still applies repository-wide.
• Only the framework checks run per subdirectory; other ignores (e.g. tests/*:S) remain root-relative.
• A subdirectory is detected only by a tracked requirements.txt or pyproject.toml.

🤖 Generated with Claude Code