DM audit: stop group messages leaking into 1:1 threads/list (1.2.42)

NIP-17 group messages (rumor with >1 recipient p-tag) were bleeding into the
1:1 surfaces:

- useConversation (thread view): a group message from `otherPubkey` where I was
  also a recipient satisfied isFromOther && isToMe, so group chatter appeared
  inside the 1:1 thread.
- useConversations (list): group messages were collapsed to conversationWith =
  sender (or an arbitrary recipient for my own sends), spawning phantom 1:1
  entries and double-listing every group (once here, once in
  useGroupConversations).

Both 1:1 hooks now skip any rumor with more than one p-tag. Groups remain the
sole responsibility of the useGroupConversation(s) hooks, which already require
pTags.length > 1. Genuine 1:1 rumors carry exactly one recipient p-tag
(createRumor doesn't tag the sender), so no legitimate message is dropped.

Verified solid (no changes): the seal(13)/rumor(14) kind checks, the
rumor.pubkey === seal.pubkey impersonation guard, and the amberSafeQueryOptions
decrypt-storm protection for interactive signers are all correct.

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

package.json

@@ -1,7 +1,7 @@
 {
   "name": "skate-spots",
   "private": true,
-  "version": "1.2.41",
+  "version": "1.2.42",
   "type": "module",
   "homepage": "https://skate-spots.com",
   "scripts": {

src/hooks/useDirectMessages.ts

@@ -322,6 +322,12 @@ export function useConversation(otherPubkey: string) {
 
           // Check if this message is part of the conversation with otherPubkey
           const pTags = rumor.tags.filter(t => t[0] === 'p').map(t => t[1]);
+
+          // 1:1 only. A rumor with more than one recipient is a GROUP message
+          // (handled by useGroupConversation). Without this guard a group chat
+          // leaks into the 1:1 thread with each of its participants.
+          if (pTags.length > 1) continue;
+
           const isFromOther = rumor.pubkey === otherPubkey;
           const isToOther = pTags.includes(otherPubkey);
           const isFromMe = rumor.pubkey === user.pubkey;
@@ -428,6 +434,13 @@ export function useConversations() {
 
           // Determine conversation partner
           const pTags = rumor.tags.filter(t => t[0] === 'p').map(t => t[1]);
+
+          // 1:1 list only. A rumor addressed to more than one recipient is a
+          // GROUP message (surfaced by useGroupConversations). Without this
+          // guard each group would masquerade as a phantom 1:1 with whichever
+          // participant happened to speak, and would appear twice in the UI.
+          if (pTags.length > 1) continue;
+
           let conversationWith: string;
 
           if (rumor.pubkey === user.pubkey) {