fix(conv-key): bootstrap re-fetches canonical key after share to handle concurrent race

packages/shared/src/chat/convKeys.ts

@@ -110,7 +110,26 @@ export async function bootstrapConvKey(
     p_bundles: bundles,
   });
   if (error) throw error;
-  const handle = { conversationId, keyVersion, key: convKey };
+
+  // `share_conv_keys` uses `ON CONFLICT (conv, recipient_user_id, key_version)
+  // DO NOTHING`. If a concurrent peer bootstrapped first at the same version,
+  // OUR INSERTs were silently skipped server-side and the row on the server
+  // holds THEIR conv-key, not ours. Trusting the locally-generated key here
+  // would leave both clients with mutually un-decryptable bundles (each
+  // encrypting/decrypting with its own key — exactly the bug that broke
+  // conv aae12d84). Re-fetch our own bundle and unwrap to get the CANONICAL
+  // server key. Whoever wrote first wins; the loser converges.
+  const ownBundle = await fetchKeyBundle(client, conversationId, own.userId, keyVersion);
+  if (!ownBundle) {
+    throw new Error('bootstrapConvKey: own bundle missing after share_conv_keys');
+  }
+  const canonicalKey = await unwrapConvKey(
+    ownBundle.encryptedKey,
+    ownBundle.nonce,
+    ownBundle.sender.senderPublicKey,
+    own.privateKey,
+  );
+  const handle = { conversationId, keyVersion, key: canonicalKey };
   cache.set(cacheKey(conversationId, keyVersion), handle);
   return handle;
 }