feat(l1): GET /accounts/me/seats endpoint for seat counter widget

Returns {engineer: SeatCheckResult, l1_tech: SeatCheckResult} for the
authenticated engineer's account. Powers the SeatCounterWidget UI in the
admin/users + account/users surfaces. Engineer+ access only.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/app/api/endpoints/accounts.py

@@ -23,8 +23,9 @@ from app.schemas.account import AccountResponse, AccountUpdate, AccountInviteCre
 from app.schemas.subscription import SubscriptionResponse, PlanLimitsResponse, UsageResponse, SubscriptionDetails
 from app.schemas.user import UserResponse, AccountRoleUpdate
 from app.core.security import verify_password
-from app.api.deps import get_current_active_user, require_account_owner
-from app.services.seat_enforcement import check_seat_available
+from app.api.deps import get_current_active_user, require_account_owner, require_engineer_or_admin
+from app.services.seat_enforcement import check_seat_available, get_seat_usage
+from app.schemas.seat_enforcement import SeatUsage
 
 _SEAT_CHECKED_ROLES = frozenset({"engineer", "l1_tech"})
 
@@ -128,6 +129,41 @@ async def get_my_members(
     return result.scalars().all()
 
 
+@router.get("/me/seats", response_model=SeatUsage)
+async def get_my_account_seat_usage(
+    db: Annotated[AsyncSession, Depends(get_db)],
+    current_user: Annotated[User, Depends(require_engineer_or_admin)],
+):
+    """Returns engineer + l1_tech seat-usage counts. Accessible to engineer+.
+
+    Powers the SeatCounterWidget on admin/users and account/users surfaces.
+    """
+    account = await _load_account(db, current_user.account_id)
+    sub = await get_account_subscription(current_user.account_id, db)
+    if sub is None:
+        # No subscription → treat as unlimited; return live counts with no limit
+        from sqlalchemy import func
+        engineer_count = (await db.execute(
+            select(func.count(User.id))
+            .where(User.account_id == account.id)
+            .where(User.account_role == "engineer")
+            .where(User.is_active.is_(True))
+        )).scalar_one()
+        l1_count = (await db.execute(
+            select(func.count(User.id))
+            .where(User.account_id == account.id)
+            .where(User.account_role == "l1_tech")
+            .where(User.is_active.is_(True))
+        )).scalar_one()
+        from app.schemas.seat_enforcement import SeatCheckResult
+        return SeatUsage(
+            engineer=SeatCheckResult(available=True, current=engineer_count, limit=None, role="engineer"),
+            l1_tech=SeatCheckResult(available=True, current=l1_count, limit=None, role="l1_tech"),
+        )
+    engineer, l1_tech = await get_seat_usage(account, sub, db)
+    return SeatUsage(engineer=engineer, l1_tech=l1_tech)
+
+
 @router.patch("/me", response_model=AccountResponse)
 async def update_my_account(
     data: AccountUpdate,