fix(client): degrade against a node still speaking MNP 1.0

The SPA is served by the hub, so deploying the hub puts this client in front of
every node — including the ones not updated yet. That window is the normal
state for as long as an operator takes, and for a node someone else runs it may
be indefinite. Three controls were broken across it, and the failure mode is
quiet: an unknown message type is logged by the node and never answered, so the
click produces a thirty-second wait ending in a timeout with nothing on screen
to say the node simply cannot do this.

Files' Upload button read `root.writable`, which a 1.0 node does not send — it
says `upload`, the same answer under the older name. The button disappeared on
every un-upgraded node. It reads both now, and still respects an explicit
`writable: false` rather than falling through to the legacy flag.

The per-app folder pickers spoke `app_directories`. Videos, Music and Photos
each had their own message before that and those still work, so the page
chooses by version: an operator on an older node keeps the ability they had.
`video_root` and `audio_root` hold one folder, so several are refused with a
reason rather than stored as the first and silently truncated.

Root management — writable, removable, eject, plug — has no older equivalent to
route to, so the table goes read-only with a line saying why and pointing at
the `meshbay-node root` commands. Chat's two settings are new with nothing
before them and are hidden the same way.

None of this was inferred from a payload's shape: `_checkNodeVersion` already
parsed the node's version and threw it away, and it is kept now. Coupling a
capability to whether some field happens to be present is how a flag flips
because an unrelated payload changed.

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

1 files changed, 21 insertions, 3 deletions

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 5d0ab07..f8b4aa5 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/group-settings.js
@@ -361,7 +361,8 @@ function GroupSettingsPanel({ groupId, group, token, transportRef, gekRef,
                              enabledApps, onEnabledApps,
                              scanSettings, onScanSettings,
                              entries, nodeDirs,
-                             appSettings, onAppDirectories, onRefreshIndex,
+                             appSettings, nodeSupportsAppOps,
+                             onAppDirectories, onRefreshIndex,
                              onPaired, onLeft }) {
   const [members, setMembers] = useState([]);
   const [adminId, setAdminId] = useState('');
@@ -647,7 +648,14 @@ function GroupSettingsPanel({ groupId, group, token, transportRef, gekRef,
     if (!transport || !transport.connected) {
       throw new Error(t('node.root_no_route'));
     }
-    await transport.setAppDirectories(appKey, paths, adminSignFn);
+    // A node too old for the generic op still answers the three per-app
+    // messages that came before it, so an operator on one keeps the ability
+    // they had rather than being handed a control that times out.
+    if (transport.supportsAppOps) {
+      await transport.setAppDirectories(appKey, paths, adminSignFn);
+    } else {
+      await transport.setAppDirectoriesLegacy(appKey, paths, adminSignFn);
+    }
     if (onAppDirectories) onAppDirectories(appKey, paths);
   }, [transportRef, adminSignFn, onAppDirectories]);
 
@@ -845,11 +853,19 @@ function GroupSettingsPanel({ groupId, group, token, transportRef, gekRef,
           <p class="settings-hint">${t('settings_node.shared_directories_hint')}</p>
           ${!connected && nodeDetected && html`
             <p class="settings-hint">${t('settings_node.roots_offline_hint')}</p>`}
+          ${/* Read-only against a node that predates the root operations:
+                writable, removable, eject and plug have no older equivalent
+                to fall back to, and an unknown message type is dropped
+                unanswered — a thirty-second wait ending in a timeout, with
+                nothing on screen to say the node simply cannot do it. */''}
+          ${connected && !nodeSupportsAppOps && !nodeDetected && html`
+            <p class="settings-hint">${t('settings_node.roots_node_too_old')}</p>`}
           <${SharedDirectoriesTable}
             roots=${effectiveRoots}
             groupId=${groupId}
             transport=${transportRef.current}
             signFn=${adminSignFn}
+            readOnly=${connected && !nodeSupportsAppOps && !nodeDetected}
             nodeDetected=${nodeDetected}
             onRootsChange=${loadNodeInfo}
             onRefreshIndex=${onRefreshIndex} />
@@ -876,7 +892,9 @@ function GroupSettingsPanel({ groupId, group, token, transportRef, gekRef,
             disabled=${appsBusy}
             onChange=${() => toggleApp(app.key)} />
         `}>
-          ${activeApps.includes(app.key)
+          ${!nodeSupportsAppOps && app.key === 'chat'
+            ? html`<p class="settings-hint">${t('settings_node.app_node_too_old')}</p>`
+            : activeApps.includes(app.key)
             ? html`<${app.Settings}
                 roots=${effectiveRoots} dirs=${folderOptions}
                 settings=${appSettings}