can
This skill implements Clock-Address-Nameable (CAN) naming and local storage/indexing (e.g., `~/.can/store`, `~/.can/index.tsv`) to stamp, verify, and find content. It instructs running shell commands (`sha256sum`, `cp`, `find`), using a private key at `~/.can/nostr.key` or `$NOSTR_PRIVKEY`, and exchanging records over networks such as `https://github.com/xccx/can`.