feat: let the operator purge a group's chat (MNP 6.1)

Signed chat_purge from the Chat settings deletes every stored message;
epoch keys and attachments stay. The ack is broadcast so open chat
panels empty.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index fa5d28b..e995ffe 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -197,7 +197,7 @@ function _aborted() {
 const BROADCAST_ACK_TYPES = new Set([
   'root_eject_ack', 'root_plug_ack', 'root_remove_ack',
   'app_directories_ack', 'chat_directory_ack', 'chat_link_preview_ack',
-  'chat_epoch_ack', 'search_listed_ack',
+  'chat_epoch_ack', 'chat_purge_ack', 'search_listed_ack',
 ]);
 
 /** Hand a broadcast ack to the callback that would have had it from a peer. */
@@ -212,6 +212,8 @@ function _replayBroadcast(transport, msg) {
     transport._onSearchListed(msg.listed !== false);
   } else if (msg.type === 'chat_epoch_ack') {
     transport._applyChatEpoch(msg);
+  } else if (msg.type === 'chat_purge_ack') {
+    if (transport._onChatPurged) transport._onChatPurged();
   } else if (transport._onRootsChanged) {
     transport._onRootsChanged(msg);
   }
@@ -223,7 +225,7 @@ const ADMIN_OP_TYPES = new Set([
   'apps_enabled', 'set_scan_settings', 'member_revoke',
   'root_remove', 'root_eject', 'root_plug',
   'app_directories', 'chat_directory', 'chat_link_preview', 'chat_epoch',
-  'search_listed', 'invite_create', 'invite_link_create', 'invite_cancel',
+  'chat_purge', 'search_listed', 'invite_create', 'invite_link_create', 'invite_cancel',
 ]);
 
 // ── Diagnostic trace (opt-in, off by default) ───────────────────────────────
@@ -545,6 +547,7 @@ class MeshBayTransport {
     this._recvBuf = new Uint8Array(0);
     this._connected = false;
     this._onChat = null;
+    this._onChatPurged = null;
     this._onStreamInit = null;
     this._onStreamData = null;
     this._onStreamEnd = null;
@@ -625,6 +628,7 @@ class MeshBayTransport {
   get reconnecting() { return !!this._reconnectPromise; }
 
   set onChat(fn) { this._onChat = fn; }
+  set onChatPurged(fn) { this._onChatPurged = fn; }
   set onStreamInit(fn) { this._onStreamInit = fn; }
   set onStreamData(fn) { this._onStreamData = fn; }
   set onStreamEnd(fn) { this._onStreamEnd = fn; }
@@ -1996,6 +2000,11 @@ class MeshBayTransport {
       this._applyChatEpoch(msg);
       return;
     }
+    // The operator purged the group's chat: every open panel empties.
+    if (msg.type === 'chat_purge_ack') {
+      if (this._onChatPurged) this._onChatPurged();
+      return;
+    }
 
     // Node-wide (not per-group) — the operator supplied/cleared a custom
     // token, or changed the query language. `token_customized` only says