Double free / use-after-free in `Chunk` and `InlineArray` removal methods when an element's `Drop` panics

Summary

`Chunk::{clear, drop_left, drop_right}` and `InlineArray::{clear, truncate}` drop the removed elements before updating the metadata that records which slots hold live values — the `left`/`right` index pair for `Chunk`, the length field for `InlineArray`. If an element's `Drop` panics during the drop, that update is never reached, so the collection still treats the already-dropped elements as live. When the collection is later dropped (its destructor walks the range described by the stale metadata), or a subsequent operation touches the same slots, those elements are dropped a second time — a double free (CWE-415) / use-after-free (CWE-416) reachable from safe Rust.

The stale field is `left` and `right` for `Chunk::clear`, `left` for `drop_left`, `right` for `drop_right`, and the length field for both `InlineArray` methods.

## Mitigation

Upgrade to `imbl-sized-chunks` 0.2.0 or later, which commits the metadata before dropping any element (fixed in jneem/imbl-sized-chunks#14, released in 0.2.0).