feat(persistence): PostgreSQL assistant store, chat persist fixes, gateway scripts

- Add SQLAlchemy Core repos, pg adapter/compat, assistant_store factory, Alembic bootstrap and migration/cutover scripts.

- Harden chat_message writes (NUL scrub for PG), turn_uuid on attempt failure, WS turn_runner fallbacks and gateway executed_turn_uuid init.

- start_gateway: log paths, PS7 stderr handling via cmd, background stdout/stderr redirect; runtime assistant_runtime_log_dir export.

- Ops: clear_all_chat_sessions with PG-only --postgresql and env-gated wipe; clear_postgres_chat_sessions.ps1.

- Tests: SA repos, pg compat, persist fallback, smoke env isolation; CI and docs touch-ups.

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

tests/test_sa_admin_user_stats_tool_health.py

@@ -0,0 +1,78 @@
+"""SA migration: list_admin_user_stats + list_session_tool_health."""
+
+from __future__ import annotations
+
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+from svc.persistence.db.engine import clear_assistant_engine_cache
+from svc.persistence.sqlite_store import SqliteStore
+
+
+@pytest.fixture
+def fresh_sqlite_store(monkeypatch: pytest.MonkeyPatch, tmp_path):
+    monkeypatch.delenv("AIA_ASSISTANT_DB_BACKEND", raising=False)
+    monkeypatch.setenv("OPS_WORKSPACE_ROOT", str(tmp_path))
+    dbfile = tmp_path / "sa_admin_th.sqlite"
+    monkeypatch.setenv("AIA_ASSISTANT_DB_PATH", str(dbfile))
+    clear_assistant_engine_cache()
+    s = SqliteStore(str(dbfile))
+    try:
+        yield s
+    finally:
+        clear_assistant_engine_cache()
+
+
+def test_sa_list_admin_user_stats_tokens_sessions_logins(fresh_sqlite_store: SqliteStore) -> None:
+    s = fresh_sqlite_store
+    t = s.create_tenant("StatsT")
+    u = s.create_user(tenant_id=t["id"], display_name="Stats User", role="member")
+    sess = s.create_session_for_user(title="Sess", tenant_id=t["id"], user_id=u["id"])
+    s.add_message(sess.id, "user", "hi")
+    s.add_trace_event(
+        session_id=sess.id,
+        trace_id="tr1",
+        span_id="sp1",
+        parent_span_id=None,
+        event_type="llm",
+        payload={"prompt_tokens_est": 12, "response_tokens_est": 3},
+    )
+    exp = (datetime.now(timezone.utc) + timedelta(days=1)).isoformat()
+    s.create_auth_session(
+        session_token_hash="tok_stats_" + sess.id[:8],
+        tenant_id=t["id"],
+        user_id=u["id"],
+        role="member",
+        expires_at=exp,
+    )
+    total, users, totals = s.list_admin_user_stats(tenant_id=t["id"], limit=50, offset=0)
+    assert total >= 1
+    row = next(x for x in users if x["user_id"] == u["id"])
+    assert row["sessions_count"] >= 1
+    assert row["total_tokens_est"] == 15
+    assert totals["users_count"] == total
+    assert totals["active_sessions_30m"] >= 1
+    assert totals["active_logins_30m"] >= 1
+
+
+def test_sa_list_session_tool_health_warn_then_ok(fresh_sqlite_store: SqliteStore) -> None:
+    s = fresh_sqlite_store
+    sess = s.create_session("TH")
+    s.add_message(sess.id, "assistant", "only assistant")
+    rows = s.list_session_tool_health(session_id=sess.id, limit=10)
+    assert len(rows) == 1
+    assert rows[0]["status"] == "warn_no_tool_calls"
+    assert rows[0]["assistant_count"] == 1
+    s.add_tool_log(sess.id, "grep", {}, {"ok": True})
+    rows2 = s.list_session_tool_health(session_id=sess.id, limit=10)
+    assert rows2[0]["status"] == "ok"
+    assert rows2[0]["tool_count"] >= 1
+
+
+def test_sa_list_session_tool_health_mcp_count(fresh_sqlite_store: SqliteStore) -> None:
+    s = fresh_sqlite_store
+    sess = s.create_session("MCP")
+    s.add_tool_log(sess.id, "mcp__srv1__ping", {}, {"ok": True})
+    rows = s.list_session_tool_health(session_id=sess.id, limit=10)
+    assert rows[0]["mcp_tool_count"] == 1