refactor: remove dead session code

src/beaver_gateway/storage/db.py

@@ -22,7 +22,7 @@ from sqlalchemy.ext.asyncio import create_async_engine
 from sqlmodel import SQLModel, select
 from sqlmodel.ext.asyncio.session import AsyncSession
 
-from beaver_gateway.storage.models import AuditLog, Session, Token
+from beaver_gateway.storage.models import AuditLog, Token
 
 if TYPE_CHECKING:
     from collections.abc import Sequence
@@ -143,45 +143,6 @@ async def touch_token(session: AsyncSession, *, token_id: int) -> None:
     await session.commit()
 
 
-# ---- Session bookkeeping ------------------------------------------------
-
-
-async def upsert_session(
-    session: AsyncSession, *, session_id: str, agent_name: str, fingerprint: str
-) -> Session:
-    """Insert-or-bump a Session row. Agent/fingerprint never change for an id."""
-    row = await session.get(Session, session_id)
-    if row is None:
-        row = Session(id=session_id, agent_name=agent_name, fingerprint=fingerprint)
-    else:
-        row.last_active_at = _utcnow()
-    session.add(row)
-    await session.commit()
-    await session.refresh(row)
-    return row
-
-
-async def touch_session(session: AsyncSession, *, session_id: str) -> None:
-    """Bump ``last_active_at`` without changing fingerprint/agent."""
-    row = await session.get(Session, session_id)
-    if row is None:
-        return
-    row.last_active_at = _utcnow()
-    session.add(row)
-    await session.commit()
-
-
-async def close_session(session: AsyncSession, *, session_id: str) -> bool:
-    """Mark a session closed. Returns ``False`` if no such row."""
-    row = await session.get(Session, session_id)
-    if row is None or row.closed_at is not None:
-        return False
-    row.closed_at = _utcnow()
-    session.add(row)
-    await session.commit()
-    return True
-
-
 # ---- Audit --------------------------------------------------------------
 
 
@@ -225,13 +186,10 @@ async def list_audit_records(
 __all__ = [
     "Database",
     "append_audit",
-    "close_session",
     "create_token",
     "list_active_tokens",
     "list_audit_records",
     "list_tokens",
     "revoke_token",
-    "touch_session",
     "touch_token",
-    "upsert_session",
 ]