fix(kb): stop DROP INDEX killing HNSW via Ladybug ghost catalog

Ladybug 0.19 DROP INDEX leaves `_0_Leaf_vec_UPPER` / `0_id_docs` in catalog so
CREATE fails while SHOW_INDEXES omits the index; create_fts_and_vector used to
swallow that. Never drop FTS/VECTOR; ensure_indexes after upserts; rebuild =
delete kb.lbug. Add compose.edelweiss.yml + regression tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

qa/load_test_bulk.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+"""Load test: bulk insert performance (writing facts to the brain)."""
+from __future__ import annotations
+
+import json
+import time
+import sys
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+sys.path.insert(0, str(ROOT / "bin" / "tools"))
+
+from kblib import connect, init_schema, upsert_leaf, ensure_indexes
+from model2vec import StaticModel
+
+
+DB_PATH = ROOT / "var" / "kb.lbug"
+
+
+def run_bulk_tests(count: int = 100, _drop_indexes: bool = True) -> dict:
+    results: dict = {}
+
+    print(f"Bulk insert test: {count} leafs")
+
+    # Fresh DB for load test — never DROP INDEX on a live catalog.
+    if DB_PATH.exists():
+        DB_PATH.unlink()
+
+    db, conn = connect(str(DB_PATH), read_only=False)
+    init_schema(conn)
+
+    model = StaticModel.from_pretrained("minishlab/potion-multilingual-128M")
+
+    t0 = time.time()
+    for i in range(count):
+        text = f"bulk load test fact {i:03d} running container on host"
+        emb = model.encode([text])[0].astype(float).tolist()
+        upsert_leaf(
+            conn,
+            text=text,
+            root="facts",
+            confidence="confirmed",
+            source="load-test",
+            source_rev="2dph",
+            how="load_test_bulk",
+            loc=f"test:{i}",
+            type_="fact",
+            embedding=emb,
+        )
+    t1 = time.time()
+
+    # Create indexes once after bulk write (DROP+recreate is unsafe on Ladybug 0.19).
+    ensure_indexes(conn)
+
+    conn.close()
+    db.close()
+
+    elapsed = t1 - t0
+    results["total_seconds"] = elapsed
+    results["throughput"] = count / elapsed  # leafs/sec
+    results["count"] = count
+    return results
+
+
+def main():
+    count_str = sys.argv[1] if len(sys.argv) > 1 else "200"
+    count = int(count_str)
+    drop_str = sys.argv[2] if len(sys.argv) > 2 else "true"
+    drop_indexes = drop_str.lower() in ("1", "true", "yes")
+
+    r = run_bulk_tests(count=count, _drop_indexes=drop_indexes)
+    print(json.dumps(r, indent=2))
+
+
+if __name__ == "__main__":
+    main()