Add /docs/ directory with user and technical documentation extracted from README, AGENTS.md, and source code. Add scripts/sync_wiki.py to sync docs to Gitea wiki via API. Add scripts/doc_coverage.py to check CLI commands, modules, and CI scripts are documented. Add sync-wiki.yml workflow for auto-sync on merge and release. Slim down README.md to lean entry point. 28 new unit tests, 100% coverage maintained.
Closes GRM-36
