fix(ui): group creation error, chat UUIDs, file preview, action menu

Bug fixes:
- Group creation "[object Object]" error: removed dead pkcs8 import code
  that threw before GEK wrapping, added array detail handling in hubFetch
- Chat shows usernames instead of UUIDs (sender_name passed through node)
- Join button: navigate to group on "Already a member" instead of error

UI improvements:
- Loading spinner animation for async states (connecting, fetching)
- File action menu (3-dot dropdown: View, Download, Play)
- Click filename to preview inline (images, text/code files)
- FilePreview overlay for images and text files
- Chat file attachment button (upload to node + structured message)
- Chat attachment display (icon, filename, size)
- Member panel: "Group admin" badge instead of plain "Admin" text

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
index 94d9b04..07ceed3 100644
--- a/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
+++ b/packages/meshbay-node/src/meshbay_node/transport/webrtc_server.py
@@ -266,6 +266,9 @@ class WebRTCPeerSession:
     def _do_chat_message(self, msg: dict) -> None:
         chat_store = self._ctx.get("chat_store")
         payload = msg.get("payload", "")
+        sender_name = msg.get("sender_name", "")
+        if sender_name:
+            self._ctx.setdefault("_user_names", {})[self._user_id] = sender_name
         if chat_store:
             raw = payload.encode() if isinstance(payload, str) else payload
             asyncio.ensure_future(chat_store.save_message(
@@ -280,6 +283,7 @@ class WebRTCPeerSession:
             "type": MNP.CHAT_MESSAGE,
             "v": MNP_VERSION,
             "sender_id": msg.get("sender_id", self._user_id),
+            "sender_name": sender_name,
             "payload": payload,
             "thread_id": msg.get("thread_id"),
             "timestamp": __import__("time").time(),
@@ -309,6 +313,7 @@ class WebRTCPeerSession:
 
     async def _send_chat_history(self, chat_store, since: float, limit: int) -> None:
         msgs = await chat_store.get_messages(since=since, limit=limit)
+        names = self._ctx.get("_user_names", {})
         self._send({
             "type": MNP.CHAT_HISTORY_RESPONSE,
             "v": MNP_VERSION,
@@ -316,6 +321,7 @@ class WebRTCPeerSession:
                 {
                     "id": m.id,
                     "sender_id": m.sender_id,
+                    "sender_name": names.get(m.sender_id, ""),
                     "payload": m.payload.decode("utf-8", errors="replace")
                     if isinstance(m.payload, bytes) else m.payload,
                     "timestamp": m.timestamp,