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, 20 insertions, 0 deletions

diff --git a/packages/meshbay-hub/tests/test_app_settings_plugin.py b/packages/meshbay-hub/tests/test_app_settings_plugin.py
index a56d70f..d469d8a 100644
--- a/packages/meshbay-hub/tests/test_app_settings_plugin.py
+++ b/packages/meshbay-hub/tests/test_app_settings_plugin.py
@@ -391,3 +391,23 @@ def test_a_saved_setting_reaches_the_page_that_renders_the_pane():
     replay = replay[:replay.index("\n}") + 2]
     for cb in ("_onChatDirectory", "_onChatLinkPreview", "_onAppDirectories"):
         assert cb in replay, f"{cb} is never called for the requester"
+
+
+def test_a_purge_empties_the_operators_own_chat_too():
+    """The same trap for `chat_purge`: the operator who purged is the one whose
+    request would swallow the broadcast, and their chat would stay full."""
+    transport = transport_source()
+    block = transport[transport.index("const BROADCAST_ACK_TYPES"):]
+    assert "'chat_purge_ack'" in block[:block.index("]);")]
+    replay = transport[transport.index("function _replayBroadcast"):]
+    replay = replay[:replay.index("\n}") + 2]
+    assert "_onChatPurged" in replay
+
+    chat = (STATIC / "chat-app.js").read_text(encoding="utf-8")
+    hook = chat[chat.index("transport.onChatPurged = "):]
+    hook = hook[:hook.index("};")]
+    assert "setMessages([])" in hook and "setHasMore(false)" in hook
+    assert "transport.onChatPurged = null" in chat, "a closed panel keeps the hook"
+
+    pane = (STATIC / "chat-app-settings.js").read_text(encoding="utf-8")
+    assert "transport.purgeChat(signFn)" in pane