Captures the framework architecture, the docker-based PHP/Composer
runtime, the components-outer game subtree convention, the
PatternParser-and-named-groups gotcha, the workflow conventions that
emerged during the rename and ProjectZomboid build-out, and the
synthetic-only fixture rule for committed test data. Adds .claude/ and
.claude.local.md to .gitignore so Claude session state and personal
overrides don't ride along.
