- Rewrite README with features, usage, and links
- Bump tesseras-dht dependency from 0.1.0 to 0.1.1
- Add CODE_OF_CONDUCT.md and SECURITY.md

- tp: limit stdin to 64 KiB + 1 byte to reject oversized pastes
  early without unbounded memory allocation
- daemon: bound the oversized-line drain to MAX_LINE_SIZE so a
  client without newlines cannot block beyond the read timeout
- tpd: document intentional Arc::into_raw leak in signal handler

- Write identity.key with mode 0600 to prevent other users from
  reading the Ed25519 private seed
- Use destination filename in atomic_write temp path to avoid
  collisions between concurrent writes to different files
- Reject HTTP methods other than GET/HEAD with 405
- Return "Hello Tesseras World" on GET /

Add reference to pledgereq[] in /usr/src/sys/kern/kern_pledge.c
and include drm and prot_exec that were missing from the list.

Warn when set_nonblocking or set_read_timeout fails instead of
silently disconnecting the client.

A slow connection or DHT lookup (up to 30s) no longer blocks
the entire HTTP accept loop. Connections beyond the limit get
a 503 response.

Report the actual error instead of silently ignoring it and
failing later with a confusing message in PasteStore::open.

- Atomic writes in store (write-to-temp + rename) to prevent
  corruption on crash
- Validate DHT results against requested content hash to reject
  forged data from malicious nodes
- Limit protocol line size to 128 KiB on Unix socket to prevent
  memory exhaustion
- Use saturating_add for TTL expiry to prevent u64 overflow