fix(client): Save in the app panes was invisible, and Chat's never landed

Two defects behind one report — "you cannot always click Save, you do not
notice, and it does not work".

**It did not work, for Chat, systematically.** `_dispatch` resolves an admin ack
against the pending request and returns, which is right for an op whose caller
already knows the value it chose. Chat's pane calls `transport.setChatDirectory`
itself, so nothing told `group-page` anything: the node saved it, every *other*
connected client learned it from the broadcast, and the one that asked went on
showing an unsaved-looking draft. Clicking Save again just re-sent it. Same
shape as the root-ack bug, in a different message — so the set is now
`BROADCAST_ACK_TYPES`, named for the property that makes it true, and covers
`chat_directory`, `chat_link_preview` and `app_directories`.

**You could not notice, because Save was not visibly a button.** It carried
`btn btn-small btn-secondary`, and there is no `.btn` rule in the stylesheet at
all — so it took `.btn-secondary`: no background, a transparent border, dim grey
text. Enabled it already looked like a disabled control; disabled it was the
same thing at 40% opacity. Measured on a real page: enabled is now accent on
white, disabled is grey text on a plain border, and an inert one says why
("No changes to save") rather than leaving the reader to guess what the pane
counts as a change. Videos' second Save — the TMDB one — is the same control,
because two Save buttons in one pane that do not look alike is worse than
either looking wrong.

Verified by driving the real pane in Electron through the whole cycle: inert,
pick a folder, live, save, and the node's answer coming back to disable it
again. Four earlier readings said the enabled button was transparent; all four
were taken inside python's directory-listing page, which the app never runs in
— my scaffolding, not the code.

Hub suite only: the node package is untouched by this.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011pvMdvLBG92jyhvD5pD6us

1 files changed, 30 insertions, 8 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/transport.js b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
index 3acfd20..179292e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/transport.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/transport.js
@@ -72,13 +72,35 @@ function _aborted() {
 // change anything — `op` is already on every admin_challenge, and this
 // list is what lets a response two steps later be tied back to the right
 // one.
-// The acks whose payload is state no caller could have predicted: they carry
-// the node's whole roots table back. See the note where they are dispatched.
-const ROOT_ACK_TYPES = new Set([
+// Acks the node *broadcasts* to everyone in the group, which the requester
+// therefore also has to be handed.
+//
+// `_dispatch` resolves an admin ack against the pending request and returns,
+// which is right for an op whose caller already knows the value it chose. It is
+// wrong for these: every *other* connected client learns the change from the
+// broadcast, and the one that asked for it is the only one that does not,
+// because its own request swallowed its copy. Found twice — first on the root
+// table, then on Chat's directory, where it meant the pane went on showing an
+// unsaved-looking draft after a save that had worked.
+const BROADCAST_ACK_TYPES = new Set([
   'root_update_ack', 'root_eject_ack', 'root_plug_ack',
   'root_add_ack', 'root_remove_ack',
+  'app_directories_ack', 'chat_directory_ack', 'chat_link_preview_ack',
 ]);
 
+/** Hand a broadcast ack to the callback that would have had it from a peer. */
+function _replayBroadcast(transport, msg) {
+  if (msg.type === 'app_directories_ack' && transport._onAppDirectories) {
+    transport._onAppDirectories(msg.app, msg.directories || []);
+  } else if (msg.type === 'chat_directory_ack' && transport._onChatDirectory) {
+    transport._onChatDirectory(msg.path || '');
+  } else if (msg.type === 'chat_link_preview_ack' && transport._onChatLinkPreview) {
+    transport._onChatLinkPreview(Boolean(msg.enabled));
+  } else if (transport._onRootsChanged) {
+    transport._onRootsChanged(msg);
+  }
+}
+
 const ADMIN_OP_TYPES = new Set([
   'tmdb_override', 'tmdb_rematch', 'tmdb_config', 'tmdb_enabled', 'video_root', 'audio_root',
   'photo_roots',
@@ -2349,9 +2371,7 @@ class MeshBayTransport {
           // name it settled on. Returning here left the operator who clicked
           // Eject as the one client that never saw it happen, while every
           // other peer got the broadcast. So this one type is handed on.
-          if (ROOT_ACK_TYPES.has(msg.type) && this._onRootsChanged) {
-            this._onRootsChanged(msg);
-          }
+          if (BROADCAST_ACK_TYPES.has(msg.type)) _replayBroadcast(this, msg);
           return;
         }
       }
@@ -2486,8 +2506,10 @@ class MeshBayTransport {
     // A root's flags changed, or one was ejected, plugged, added or removed.
     // Broadcast by the node to every peer, so everyone's table updates without
     // waiting for the next index_sync.
-    if (ROOT_ACK_TYPES.has(msg.type) && this._onRootsChanged) {
-      this._onRootsChanged(msg);
+    if (msg.type === 'root_update_ack' || msg.type === 'root_eject_ack'
+        || msg.type === 'root_plug_ack' || msg.type === 'root_add_ack'
+        || msg.type === 'root_remove_ack') {
+      if (this._onRootsChanged) this._onRootsChanged(msg);
     }
 
     // The operator's node is scanning — never the entries themselves, just