refactor: remove dead session code

src/beaver_gateway/storage/__init__.py

@@ -1,40 +1,32 @@
-"""SQLModel-backed persistence (Phase 4.1).
+"""SQLModel-backed persistence.
 
-The storage layer carries three tables — :class:`Token`, :class:`Session`,
-:class:`AuditLog` — and a thin :class:`Database` wrapper around a sync
-SQLAlchemy engine. Phase 4.2 (auth migration) and Phase 4.3 (admin UI)
-build on this; Phase 4.1 itself only schemas the data and exposes the
-``Database`` on :class:`GatewayRuntime` so later phases can reach it.
+Two tables — :class:`Token`, :class:`AuditLog` — plus a thin
+:class:`Database` wrapper around an async SQLAlchemy engine. The
+``GatewayRuntime`` carries the handle so auth (token verify / touch)
+and admin (token CRUD + audit listing) can reach it.
 """
 
 from beaver_gateway.storage.db import (
     Database,
     append_audit,
-    close_session,
     create_token,
     list_active_tokens,
     list_audit_records,
     list_tokens,
     revoke_token,
-    touch_session,
     touch_token,
-    upsert_session,
 )
-from beaver_gateway.storage.models import AuditLog, Session, Token
+from beaver_gateway.storage.models import AuditLog, Token
 
 __all__ = [
     "AuditLog",
     "Database",
-    "Session",
     "Token",
     "append_audit",
-    "close_session",
     "create_token",
     "list_active_tokens",
     "list_audit_records",
     "list_tokens",
     "revoke_token",
-    "touch_session",
     "touch_token",
-    "upsert_session",
 ]