BudgetPlanRepository

• get
  (plan_id: UUID) -> BudgetPlan | None
  Get budget plan by ID
• save
  (plan: BudgetPlan) -> None
  Insert or update a budget plan
• delete
  (plan_id: UUID) -> bool
  Delete a budget plan
• get_effective
  (owner_id: UUID, period_type: PeriodType, as_of: Date) -> BudgetPlan | None
  Get effective plan for owner/period type as of date
• list_by_owner
  (owner_id: UUID) -> list[BudgetPlan]
  List all budget plans for an owner
• query
  (spec: QuerySpec) -> QueryResult[BudgetPlan]
  Query with filters, sorting, pagination

• InMemoryBudgetPlanRepository
  from budget
  In-memory budget plan storage for testing

Not required by any components