fix: a root change reaches every client without a page reload

The directory table travelled on `index_sync` alone — a *full* index, which the
node only ever sends on request. Every ongoing change went out as an
`index_delta`, which carried files and nothing else. So the message that says
"something changed" was the one message that could not say a root had.

The acks hid it: `root_add_ack` and friends broadcast the new table to whoever
is connected, so the common cases looked right. What that could not cover was
the operator's own client, where the ack landed and was then overwritten — the
table calls `onRefreshIndex` after an add, that fetch returns the set from
*before* the node's reload (fire-and-forget, because a rescan is minutes on a
real library), and `applyIndex` writes it over what the ack had just delivered.
The new directory appeared for one paint and vanished.

Two halves. `index_delta` now carries the roots table, sealed with the rest and
identical to `index_sync`'s — additive, so a 1.0 client sees a field it does not
read. And the table no longer refreshes the index after a root change: the ack
gives it the new set immediately, and the delta the node pushes when the scan
finishes gives it again, along with the files.

The test that pins it uses an *eject* as its case, because an eject changes no
file at all — the entries freeze — so its delta is empty of additions,
deletions and updates. Without the table it says literally nothing, which is
how a library disappearing from under a group went unannounced to everyone but
whoever pressed the button.

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

2 files changed, 25 insertions, 6 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/group-page.js b/packages/meshbay-hub/src/meshbay_hub/static/group-page.js
index a1e6411..0a43724 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/group-page.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/group-page.js
@@ -244,6 +244,13 @@ function GroupPage({ groupId, group, token, username, userId, userPrefs,
   // enrichment (duration/thumb_hash/display_title/...) arriving for a file
   // already in the table — same id, new fields (see group_index.py diff()).
   const applyIndexDelta = useCallback((deltaMsg) => {
+    // The roots table rides on the delta as of MNP 1.1. Before that it
+    // travelled only on a full index_sync, which is sent on request — so a
+    // root added, removed, ejected or plugged by anyone left every other
+    // client's directory table stale until they reloaded the page.
+    if (Array.isArray(deltaMsg.roots) && deltaMsg.roots.length) {
+      setNodeRoots(deltaMsg.roots);
+    }
     setEntries((prev) => {
       const deletions = new Set(deltaMsg.deletions || []);
       const kept = prev.filter((e) => !deletions.has(e.id));
diff --git a/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js b/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js
index ce36a40..9646405 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js
@@ -42,7 +42,8 @@ import * as platform from './platform.js';
  *   nodeDetected   — whether the loopback node API answers
  *   readOnly       — suppress every edit control
  *   onRootsChange  — called after a change, to re-read the loopback list
- *   onRefreshIndex — full index refresh, needed after an add or a remove
+ *   onRefreshIndex — full index refresh. Not called after a root change: see
+ *                    `run()` for why the node's own push is what settles it
  *   mode           — "live" (default) or "local"
  *   localRoots / onLocalRootsChange — the array, in "local" mode
  */
@@ -106,18 +107,29 @@ function SharedDirectoriesTable({ roots, groupId, transport, signFn,
   const rootUrl = (name, suffix = '') =>
     '/api/groups/' + groupId + '/roots/' + encodeURIComponent(name) + suffix;
 
-  const run = useCallback(async (work, { refreshIndex = false } = {}) => {
+  // Deliberately no index refresh after a root change.
+  //
+  // Adding a root makes the node reload, which rescans — minutes on a real
+  // library — and the reload is fire-and-forget for that reason. Fetching the
+  // index in the moment after therefore returns the set from *before* it, and
+  // `applyIndex` writes that over the roots the ack had just delivered: the
+  // new directory appeared for one paint and vanished, which is what "it only
+  // shows up after a refresh" was.
+  //
+  // Nothing is lost by waiting. The ack carries the new table immediately, and
+  // the delta the node pushes when the scan finishes carries it again along
+  // with the files.
+  const run = useCallback(async (work) => {
     setBusy(true); setMsg('');
     try {
       await work();
       if (onRootsChange) await onRootsChange();
-      if (refreshIndex && onRefreshIndex) await onRefreshIndex();
       return true;
     } catch (err) {
       setMsg(platform.bridgeMessage(err));
       return false;
     } finally { setBusy(false); }
-  }, [onRootsChange, onRefreshIndex]);
+  }, [onRootsChange]);
 
   const doUpdateRoot = useCallback(async (rootName, updates) => {
     if (isLocal) {
@@ -171,7 +183,7 @@ function SharedDirectoriesTable({ roots, groupId, transport, signFn,
         await platform.node.call('DELETE', rootUrl(rootName));
         await platform.node.call('POST', '/api/reload');
       } else throw new Error(t('node.root_no_route'));
-    }, { refreshIndex: true });
+    });
     if (ok) setMsg(t('node.root_removed'));
   }, [isLocal, localRoots, onLocalRootsChange, overMnp, overLoopback,
       transport, groupId, signFn, run]);
@@ -203,7 +215,7 @@ function SharedDirectoriesTable({ roots, groupId, transport, signFn,
         await platform.node.call('POST', '/api/reload');
         await platform.watchIndexProgress(groupId, setIndexProgress);
       } else throw new Error(t('node.root_no_route'));
-    }, { refreshIndex: true });
+    });
   }, [isLocal, localRoots, onLocalRootsChange, overMnp, overLoopback,
       transport, groupId, signFn, run]);