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_tenant_bind_code.py

@@ -0,0 +1,48 @@
+"""SA migration: tenant + bind_code."""
+
+from __future__ import annotations
+
+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_tenant_bc.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_tenant_crud(fresh_sqlite_store: SqliteStore) -> None:
+    s = fresh_sqlite_store
+    t = s.create_tenant("Acme")
+    listed = s.list_tenants(limit=50)
+    assert any(x["id"] == t["id"] for x in listed)
+    assert s.delete_tenant(tenant_id=t["id"]) == 1
+    assert s.delete_tenant(tenant_id=t["id"]) == 0
+
+
+def test_sa_bind_code_list_and_consume(fresh_sqlite_store: SqliteStore) -> None:
+    s = fresh_sqlite_store
+    t = s.create_tenant("BindCo")
+    s.create_bind_code(tenant_id=t["id"], role="member", code="CODE12345")
+    rows = s.list_bind_codes(tenant_id=t["id"], limit=10)
+    assert len(rows) == 1
+    assert rows[0]["code"] == "CODE12345"
+    assert rows[0]["used_at"] is None
+    out = s.consume_bind_code(code="CODE12345", channel="wecom", external_user_id="wx-1", display_name="Ext")
+    assert out is not None
+    assert out["tenant_id"] == t["id"]
+    rows2 = s.list_bind_codes(tenant_id=t["id"], limit=10)
+    assert rows2[0]["used_at"] is not None
+    assert rows2[0]["used_by_external_user_id"] == "wx-1"
+    assert s.consume_bind_code(code="CODE12345", channel="wecom", external_user_id="wx-2") is None