feat: simplify rule patterns and local overrides

Schema And Matching
- replace dirs, files, and paths with a single gitignore-like patterns
  field across policy, runtime config, matching, and generated rules
- rename type patch removal from .drop to .rm
- normalize directory rules with trailing '/' and regenerate rules.toml

Docs And Tests
- update generator and test docs to describe patterns, .rm,
  and the explicit uv run python gen/rules.py workflow
- refresh fixtures and harness coverage for the new schema and
  bump the package version to 0.3

Tooling
- update pre-commit hook revisions and refresh the lockfile

bump version to v0.2

initial commit