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)

bin/md/import

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+import lib
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+
+from mdleaves import leaves_to_json, read_markdown, to_all, walk_markdown  # noqa: E402
+from yamlout import to_yaml  # noqa: E402
+
+
+def main(argv: list[str]) -> int:
+    import argparse
+    p = argparse.ArgumentParser(description="md/import - split markdown corpus into leafs")
+    p.add_argument("root", nargs="?", default=".", help="directory to walk for .md files")
+    p.add_argument("--files", action="store", help="comma-separated file list")
+    p.add_argument("--json", action="store_true")
+    a = p.parse_args(argv)
+
+    paths: list[Path] = []
+    if a.files:
+        paths = [Path(f) for f in a.files.split(",")]
+    else:
+        root = Path(a.root)
+        if not root.exists():
+            print(f"md/import: no such path {root}", file=sys.stderr)
+            return 2
+        paths = [root] if root.is_file() else walk_markdown(root)
+
+    if not paths:
+        print("md/import: no markdown files", file=sys.stderr)
+        return 1
+
+    all_leafs: list[dict] = []
+    for path in paths:
+        try:
+            text = read_markdown(path)
+        except OSError as e:
+            print(f"md/import: {path}: {e}", file=sys.stderr)
+            continue
+        all_leafs.extend(to_all(text, path))
+
+    out = leaves_to_json(all_leafs)
+    print(out if a.json else to_yaml(__import__("json").loads(out)))
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))