# Implementation Spec: Round 13 — COMPLETE

## New Feature

### AggregateError (mytheclipse-core, resiliency)
File: `crates/mytheclipse/src/aggregate_error.rs`
- Collects multiple `E: std::error::Error` from parallel/fan-out tasks into one
  error — natural failure type for `join_all` + batch/fan-out resilience
- `empty()` / `with_context(..)` / push(E) / is_empty / len / iter
- `from_results(Vec<Result<V,E>>) -> Result<Vec<V>, AggregateError>` — collects
  ALL errors, returns values when all Ok
- Display lists count + first error; From<Vec<Box<dyn Error>>>, Extend
- 3 tests

## Files
- new: core/src/aggregate_error.rs
- core/lib.rs: +module+export AggregateError (resiliency)

Build: exit 0. Tests: 0 FAILED (97 core pass). Clippy: 0 new warnings.