feat: copy a file's or folder's #/name@owner link from Files, Music, Photos and Search

"Copy link" puts the address group-link.js resolves on the clipboard, on the
hub's origin rather than the page's, so a link copied in the desktop
application is not app://meshbay. Files offers it for one row, from the
right-click menu or the toolbar with one row ticked (a phone's way in);
Music on one track's menu, whose dots a phone has; Photos on a right-clicked
tile and in the lightbox's bar. The video player and the file preview carry
a link button next to Download.

Applications get a `linkFor(entry | folderPath)` prop (MESHBAY_DESIGN.md
§9.2) and offer the action only when it names a link. The group page builds
it from the hub's row; Search from each result's own group and its path
before the merged views prefixed it, and names no link for a folder of the
merged tree, which a group name alone does not identify.

harness/copy_link_probe.py mounts the three applications in Chrome and reads
what reached the clipboard.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 14 insertions, 3 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 a2d6c18..48b1c80 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/group-page.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/group-page.js
@@ -6,6 +6,7 @@ import { Icon } from './icon.js';
 import { transfers } from './transfers.js';
 import { downloadEntry } from './file-utils.js';
 import { resolveLinkedPath } from './group-link.js';
+import { copyLink, entryPath, groupItemLink } from './copy-link.js';
 import {
   HUB, session, hubFetch, ensureFreshToken,
   _loadBundleKey, _loadRecoveryKey, _storeBundleKey,
@@ -761,6 +762,14 @@ function GroupPage({ groupId, group, token, username, userId, userPrefs,
     if (onLinkOpened) onLinkOpened();
   }, [openPath, status, groupId]);
 
+  // The link "Copy link" puts on the clipboard, for an entry or a folder path
+  // (group-link.js). Null until the hub's row for the group is in: the handle
+  // is its name and its owner's, and the node knows neither.
+  const linkFor = useCallback((target) => {
+    if (!group || !group.name || !group.owner_username || !target) return null;
+    return groupItemLink(group, typeof target === 'string' ? target : entryPath(target));
+  }, [group]);
+
   const refreshIndex = useCallback(async () => {
     const transport = transportRef.current;
     if (!transport || !transport.connected) return;
@@ -891,7 +900,7 @@ function GroupPage({ groupId, group, token, username, userId, userPrefs,
     entries, availableEntries, nodeDirs, nodeRoots,
     setEntries, setNodeDirs, setNodeRoots, applyIndex,
     isNodeAdmin, operatorPaired, attachRoot, attachDir, userId, setError, onPreview,
-    onRefreshIndex: refreshIndex, onActivity: touchActivity,
+    onRefreshIndex: refreshIndex, onActivity: touchActivity, linkFor,
     // Plural everywhere, and built from the registry rather than a list of app
     // names kept here: Videos and Music read a list, Photos always did, and an
     // application added to `APPS` gets its own entry without this file
@@ -1060,7 +1069,8 @@ function GroupPage({ groupId, group, token, username, userId, userPrefs,
           transportRef=${transportRef}
           gekRef=${gekRef}
           onClose=${() => setPreviewEntry(null)}
-          onDownload=${() => downloadFileForModal(previewEntry)} />
+          onDownload=${() => downloadFileForModal(previewEntry)}
+          onCopyLink=${linkFor(previewEntry) && (() => copyLink(linkFor(previewEntry)))} />
       `}
       ${videoEntry && html`
         <${VideoPlayer}
@@ -1068,7 +1078,8 @@ function GroupPage({ groupId, group, token, username, userId, userPrefs,
           transportRef=${transportRef}
           gekRef=${gekRef}
           onClose=${() => setVideoEntry(null)}
-          onDownload=${() => downloadFileForModal(videoEntry)} />
+          onDownload=${() => downloadFileForModal(videoEntry)}
+          onCopyLink=${linkFor(videoEntry) && (() => copyLink(linkFor(videoEntry)))} />
       `}
     </div>
   `;