Function reassemble 

pub fn reassemble(strings: &[&str]) -> Result<Descriptor, Error>

Reassemble a Descriptor from N md1 codex32 strings.

Algorithm:

1. Unwrap each string via the codex32 layer (verifies BCH per chunk).
2. Parse the 37-bit chunk header from each.
3. Validate consistency: same version, chunk_set_id, count.
4. Sort by index; verify 0..count-1 with no gaps.
5. Concatenate per-chunk payload bytes.
6. Decode the reassembled payload via decode_payload.
7. Verify the reassembled payload’s derived chunk-set-id matches the chunk-set-id present in every chunk header (cross-chunk integrity).