test(notifications): cover Buzz reactions in the e2e harness + document Buzz DM

- run.sh: add a Buzz-style bare reaction check (kind-7 with an `e` tag but no `p`
  tag) asserting it still lands on the Reactions channel, and a note that Buzz DM
  isn't auto-triggered.
- README: coverage row for the bare reaction, plus a "Buzz DM (manual)" section
  with the channel-setup steps (kind-39000 `t=dm` + participant, then post
  kind-9/40002) since participant-routing needs cached channel metadata.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0122uQ8BLHLeHDni81RBP26r

tools/notification-e2e/README.md

@@ -18,6 +18,7 @@ fails.
 | Mention (+ liveness) | `amy event --kind 1` p-tagging A | `MentionsID` + "mentioned you" |
 | Reply | kind 1 with `e`+`p` tags to A's note | `RepliesID` + "replied" |
 | Reaction | kind 7 to A's note | `ReactionsID` + "reacted" |
+| Buzz bare reaction | kind 7 with `e` tag, **no `p` tag** | `ReactionsID` (routed via `tagsAnEventByUser`) |
 | Repost *(new kind)* | kind 6 to A's note | `RepostsID` + "reposted" |
 | Picture *(new kind)* | kind 20 with `imeta` + `p` | `MediaID` + "shared a photo" |
 | DM | `amy dm send` | `PrivateMessagesID` + the body |
@@ -28,6 +29,25 @@ Zaps (need a Lightning wallet), git/badge/nutzap/onchain (need repo / badge
 definition / cashu proofs) aren't automated here — they follow the same
 `amy event --kind …` pattern with the appropriate tags if you want to extend it.
 
+### Buzz DM (manual)
+
+Buzz DM notifications (`StreamMessageV2Event` k40002 / `ChatEvent` k9 in a `t=dm`
+relay-group channel) are participant-routed off the channel's kind-39000
+metadata, so they can't be triggered in one `amy event` call. To verify by hand:
+
+1. Create a Buzz DM channel whose kind-39000 metadata has `["t","dm"]` and a
+   `["p", <A_hex>]` participant tag (use the Buzz UI, or `amy relaygroup` /
+   `amy event --kind 39000` as the relay/group admin), on a relay A is connected
+   to. Let A load the channel (open it once) so its 39000 metadata is cached —
+   push only fires when the participant list is known.
+2. As B, post a message into it: `amy event --kind 9 --content "buzz dm hi"
+   --tags '[["h","<groupId>"]]' --relay <groupRelay>` (or kind 40002).
+3. Background the app; expect a `PrivateMessagesID` notification titled with the
+   channel name and body `B: buzz dm hi`, tapping it opens the chatroom.
+
+The gate is intentionally strict (participant metadata must be loaded), matching
+the in-app feed — a cold push with no cached channel won't notify.
+
 ## Prerequisites
 
 - A device/emulator on `adb` with the **debug** app installed and an account

tools/notification-e2e/run.sh

@@ -145,6 +145,12 @@ if [ -n "$TARGET_ID" ]; then
   pubB 7 "🤙" "[[\"e\",\"$TARGET_ID\"],[\"p\",\"$A_HEX\"]]" >/dev/null
   wait_for "ReactionsID" "reacted" && ok "reaction → Reactions channel" || bad "reaction notification missing"
 
+  # Buzz-style bare like: a NIP-25 kind-7 with an `e` tag but NO `p` tag (Buzz
+  # relays emit these). Must still notify — routed via tagsAnEventByUser, not the
+  # p-tag gate. A distinct emoji separates it from the 🤙 reaction above.
+  pubB 7 "❤️" "[[\"e\",\"$TARGET_ID\"]]" >/dev/null
+  wait_for "ReactionsID" "❤️" && ok "Buzz bare reaction (no p-tag) → Reactions channel" || bad "Buzz bare reaction missing"
+
   pubB 6 "" "[[\"e\",\"$TARGET_ID\"],[\"p\",\"$A_HEX\"]]" >/dev/null
   wait_for "RepostsID" "reposted" && ok "repost → Reposts channel (new kind)" || bad "repost notification missing"
 else
@@ -158,6 +164,12 @@ amyB dm send "$A_NPUB" "e2e direct message" --relay "$RELAY" >/dev/null 2>&1 \
   && { wait_for "PrivateMessagesID" "e2e direct message" && ok "DM → Private Messages (MessagingStyle)" || meh "DM notification missing (check A's kind:10050 DM relays include $RELAY)"; } \
   || meh "amy dm send failed (DM relays / wallet not configured) — skipped"
 
+# Buzz DM (kind 40002 / kind 9 in a `t=dm` relay-group channel) is participant-
+# routed off the channel's 39000 metadata, which this script can't set up in one
+# shot. Not auto-triggered — see README "Buzz DM (manual)". Expect it to land on
+# PrivateMessagesID with the channel name as title and "<sender>: <text>" body.
+meh "Buzz DM not auto-triggered (needs a t=dm relay-group channel) — see README"
+
 # ---------------------------------------------------------------------------
 hdr "Observability — cold-push metadata enrichment"
 # Fresh sender C with NO profile: the notification must first show a raw pubkey,