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)

tools/test_kblib.py

@@ -0,0 +1,73 @@
+import os
+import sys
+import tempfile
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+
+import kblib  # noqa: E402
+
+
+def make_emb(value: float) -> list[float]:
+    vec = [0.0] * kblib.EMBED_DIM
+    vec[0] = value
+    return vec
+
+
+class KblibTest(unittest.TestCase):
+    def setUp(self):
+        self.dir = tempfile.mkdtemp()
+        self.dbpath = os.path.join(self.dir, "kb.lbug")
+        self.db, self.conn = kblib.connect(self.dbpath, read_only=False)
+        kblib.init_schema(self.conn)
+
+    def tearDown(self):
+        self.conn.close()
+        self.db.close()
+
+    def test_leaf_id_is_stable(self):
+        self.assertEqual(kblib.leaf_id("abc", "src"), kblib.leaf_id("abc", "src"))
+        self.assertNotEqual(kblib.leaf_id("abc", "src"), kblib.leaf_id("abd", "src"))
+
+    def test_upsert_roundtrip(self):
+        kblib.upsert_leaf(self.conn, text="the quick brown fox", root="info",
+                          confidence="confirmed", source="s", source_rev="r1",
+                          how="test", loc="/tmp", type_="reference",
+                          embedding=make_emb(1.0))
+        kblib.create_fts_and_vector(self.conn, force=True)
+        hits = kblib.query_fts(self.conn, "fox", 5)
+        self.assertEqual(len(hits), 1)
+        self.assertEqual(hits[0]["root"], "info")
+
+    def test_hybrid_ranks_vector_match(self):
+        kblib.upsert_leaf(self.conn, text="the quick brown fox", root="info",
+                          confidence="confirmed", source="s", source_rev="r1",
+                          how="test", loc="/tmp", type_="reference",
+                          embedding=make_emb(1.0))
+        kblib.upsert_leaf(self.conn, text="a lazy dog sleeps", root="info",
+                          confidence="confirmed", source="s", source_rev="r1",
+                          how="test", loc="/tmp", type_="reference",
+                          embedding=make_emb(0.0))
+        kblib.create_fts_and_vector(self.conn, force=True)
+        result = kblib.hybrid_search(self.conn, make_emb(1.0), [], 5)
+        self.assertTrue(result)
+        self.assertIn("rrf", result[0])
+        self.assertEqual(result[0]["text"], "the quick brown fox")
+
+    def test_stats_counts_roots(self):
+        kblib.upsert_leaf(self.conn, text="a fact leaf", root="facts",
+                          confidence="confirmed", source="s", source_rev="r1",
+                          how="test", loc="/tmp", type_="reference",
+                          embedding=make_emb(0.5))
+        kblib.upsert_leaf(self.conn, text="an info leaf", root="info",
+                          confidence="confirmed", source="s", source_rev="r1",
+                          how="test", loc="/tmp", type_="reference",
+                          embedding=make_emb(0.5))
+        stats = kblib.stats(self.conn)
+        self.assertEqual(stats["total"], 2)
+        self.assertEqual(stats["by_root"], {"facts": 1, "info": 1})
+
+
+if __name__ == "__main__":
+    unittest.main()