Task tool (saurun:backend-implementer):
  description: "Implement [task name]"
  prompt: |
    You are implementing [task name].

    ## Task Description
    [PASTE FULL TASK TEXT HERE - subagent cannot read plan files]

    ## Context
    [Project, bounded context, layer (Domain/Application/Infrastructure/API)]
    [Existing entities, patterns, handlers to follow]
    [Inter-task dependencies if any]

    ## Before You Begin
    If the task description above is ambiguous or missing acceptance criteria,
    ask for clarification before starting. Otherwise, proceed immediately.

    ## Your Job
    1. Implement exactly what the task specifies
    2. **REQUIRED SUB-SKILL:** Follow saurun:dotnet-tdd strictly. No exceptions.
    3. Verify implementation works: `dotnet test`
    4. Commit your work
    5. Self-review (see below)
    6. Report back

    Work from: [absolute path to backend root]

    While you work: if you encounter something unexpected or unclear, ask
    questions. Don't guess or make assumptions.

    ## Before Reporting Back: Self-Review
    [Include full self-review checklist from guide]

    ## Report Format
    - What you implemented
    - What you tested and test results
    - Files changed
    - Self-review findings (if any)
    - Any issues or concerns

Task tool (saurun:backend-implementer):
  description: "Implement AddItem endpoint for ShoppingList API"
  prompt: |
    You are implementing the AddItem endpoint for the ShoppingList API.

    ## Task Description

    Add a POST endpoint `POST /api/shopping-lists/{listId}/items` that adds an item to
    an existing shopping list. The request body contains `name` (string, required,
    max 200 chars) and `quantity` (int, required, min 1). The endpoint should:
    - Return 201 with the created item (id, name, quantity, addedAt)
    - Return 404 if the shopping list does not exist
    - Return 400 if validation fails (missing name, name too long, quantity < 1)
    - Use the ShoppingList aggregate to enforce invariants (max 50 items per list)
    - Return 409 if adding the item would exceed the 50-item limit

    ## Context

    This is in the ShoppingList bounded context. The domain layer already has a
    `ShoppingList` aggregate with an `Items` collection and a `ShoppingListItem`
    entity. The Application layer has a `IShoppingListRepository` interface.
    Follow the existing pattern from `CreateShoppingListCommandHandler` for the
    command/handler structure. The API layer uses Carter for minimal API endpoints --
    see `CreateShoppingListEndpoint.cs` for the pattern.

    No other tasks depend on this, but this task depends on the ShoppingList
    aggregate already existing (it does).

    ## Before You Begin

    If the task description above is ambiguous or missing acceptance criteria,
    ask for clarification before starting. Otherwise, proceed immediately.

    ## Your Job

    1. Implement exactly what the task specifies
    2. **REQUIRED SUB-SKILL:** Follow saurun:dotnet-tdd strictly. No exceptions.
    3. Verify implementation works: `dotnet test`
    4. Commit your work
    5. Self-review (see below)
    6. Report back

    Work from: /Users/dev/repos/shopping-app/backend

    While you work: if you encounter something unexpected or unclear, ask
    questions. Don't guess or make assumptions.

    ## Before Reporting Back: Self-Review

    Review your work with fresh eyes. Ask yourself:

    **Completeness:**
    - Did I fully implement everything in the spec?
    - Did I miss any requirements (404, 400, 409 cases)?
    - Are there edge cases I didn't handle?

    **Quality:**
    - Is this my best work?
    - Are names clear and accurate?
    - Is the code clean and maintainable?

    **Discipline:**
    - Did I avoid overbuilding (YAGNI)?
    - Did I only build what was requested?
    - Did I follow existing patterns (Carter endpoints, CQRS handlers)?

    **Testing:**
    - Did I follow TDD? (test first, watch fail, minimal code, watch pass, refactor)
    - Would each test catch a real bug? If not, delete it.
    - REFERENCE: See saurun:dotnet-tdd verification checklist.

    If you find issues during self-review, fix them now before reporting.

    ## Report Format

    When done, report:
    - What you implemented
    - What you tested and test results
    - Files changed
    - Self-review findings (if any)
    - Any issues or concerns