feat(kb): brain tools, Go async serve, root-level docker

- tools/kblib.py: ladybug schema, embeddings, FTS+vector, hybrid RRF
- bin/kb/{index,search,get,stats,eval}: corpus indexing + deduction search
- bin/facts/{extract,audit}: 2-source evidence acquisition + gates
- serve/: async Go HTTP server (goroutines, bounded worker pool), TDD
- docker/ flattened to root: compose.yaml + Dockerfile (multi-stage Go)
- docker scripts -> bin/ shebang pattern (kb-watch, docker-entrypoint)
- bin/ci/semver + tools/semver.py: conventional-commit semver release
- ci.yml: go tests + shell checks; drop release-please (PR toggle blocked)

AGENTS.md

@@ -35,8 +35,13 @@ Read first: [PLAN](PLAN.md) → [docs](docs/).
 PLAN.md       decisions + execution + open questions
 docs/         published docs
 skills/       in-project agent skills (vendored, no external links)
-bin/          self-describing tools bin/{subject}/{method}
+bin/          self-describing tools bin/{subject}/{method} (shebang)
+bin/kb-watch  corpus watcher (mtimes, no inotify deps)
+bin/docker-entrypoint  container entrypoint (brain index|search|serve|watch)
+serve/        async Go HTTP server (goroutines, bounded worker pool)
 tools/        vendored python libs behind bin/* (yamlout, websearch)
+compose.yaml  docker composition (root level, not docker/)
+Dockerfile    multi-stage: python deps + static Go serve
 var/          kb.lbug, caches (gitignored)
 .venv/        ladybug + model2vec + mistune
 ```