feat(cli): external-agent realtime path (#2663)

[Bartok9]

Closes direction toward #2663 (full external/OpenClaw CLI path). Keep #2933 open as the small users me slice.

Ships

• Option B: buzz listen — NIP-42 WS, NDJSON events, --channel / --mentions-of-me, reconnect+SIGINT, optional --webhook (Option A)
• Gap Initial release — Sprout Nostr relay with enterprise extensions #2: messages get --format compact keeps pubkey + tags
• Gaps feat: add desktop app #3–docs(readme): clarify desktop setup #4: buzz agents publish kind:30177 + client schema validation + docs/cli-external-agents.md
• Gap Dependency Dashboard #1: buzz users me included so this PR is E2E-complete (sibling feat(cli): add buzz users me for external-agent identity #2933)

Residual

• Gap Initial backend revisions, workflow expansion #5 @-mention selector (Desktop) — follow-up
• Option C generic ACP — BYOH feat(acp): bring your own harness (BYOH) — generic ACP runtime seam + settings gallery #2773, not here

Tests

cargo test -p buzz-cli --lib (264 ok) · cargo test -p buzz-ws-client --lib (3 ok)

[dspury]

I’ve been validating the resident/external-agent path against Buzz’s current relay subscription rules before opening any overlapping PR. I’m sharing the resulting branches here first so we can coordinate rather than compete with #2942/#2933.

The tested changes are split into three harness-neutral slices:

1. Identity/compact prerequisites — Lunar-Park:buzz-pr-identity (561add554, 341b37114)

   • buzz users me
   • compact pubkey/tags
   • subprocess proof that identity resolution performs no relay I/O and never prints the private key

2. Listen v1 contract — Lunar-Park:buzz-pr-listen (dbf564f2f, 7ce55d055)

   • one single-#h subscription per resolved channel, preserving the relay’s host/community security classification and live channel fan-out
   • mention-only channel discovery, aggregated EOSE, CLOSE on SIGINT/SIGTERM
   • retryable WebSocket transport failures are machine-classified as exit code 2; auth/config/protocol failures remain fatal
   • process tests for scoped multi-channel delivery, mention-only discovery, network refusal, and both shutdown signals

3. Executable conformance fixtures — Lunar-Park:buzz-pr-fixtures (dbfef894f, c723de94b)

   • exact normalization checks for schema, channel/thread validation, mentions, author policy, self-suppression, lifecycle ordering, malformed JSON, and replay deduplication

Validation on the full stack passes cargo fmt --all -- --check, cargo clippy -p buzz-cli --all-targets -- -D warnings, and cargo test -p buzz-cli (267 unit tests plus the identity, listen, and fixture process/contract tests).

Would you prefer these as suggested commits on #2942/#2933, a split of #2942 into the smaller identity/listen units, or another coordination path? I’ll hold off on opening a competing upstream PR until we agree on the cleanest route.