None of the agentic markdown tags for running follow-up scripts are included yet, but this at least gets most of the content out there.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

- atproto/xrpc.rkt: use "&" not "," to join query params. The
comma produced invalid URLs like ?limit=10,actor=foo instead
of ?limit=10&actor=foo. Unnoticed so far as all current calls
pass only one param.
- bluesky/open-app.rkt: add missing ")" in feed option printf
format string, closing the option's parenthesized command span.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

read-dms.sh now records a read timestamp to ~/.claude-social/dms-last-read.json
after fetching messages. send-dm.sh checks this file before sending and refuses
if the conversation wasn't read within the last 10 minutes, with a clear error
message to re-read first.

This mirrors how chat UIs work: you see prior messages before composing a reply.

In atproto-lookup-pds, add a note that the function currently only handles
did:plc: DIDs and would require additional implementation for did:web: DIDs.

Per Jacqueline's request for clarity in the code about supported DID schemes.

Signed-off-by: Jack Firth <jackhfirth@gmail.com>