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, 6 insertions, 1 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/video-player.js b/packages/meshbay-hub/src/meshbay_hub/static/video-player.js
index 37ea727..21abe8e 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/video-player.js
+++ b/packages/meshbay-hub/src/meshbay_hub/static/video-player.js
@@ -403,7 +403,7 @@ function purgeUnscopedResumePositions() {
 
 purgeUnscopedResumePositions();
 
-function VideoPlayer({ entry, transportRef, gekRef, onClose, onDownload }) {
+function VideoPlayer({ entry, transportRef, gekRef, onClose, onDownload, onCopyLink }) {
   const [dlBusy, setDlBusy] = useState(false);
   const [phase, setPhase] = useState('loading');
   const [error, setError] = useState('');
@@ -1957,6 +1957,11 @@ function VideoPlayer({ entry, transportRef, gekRef, onClose, onDownload }) {
             }
           </span>
         `}
+        ${onCopyLink && html`
+          <button class="video-close" onClick=${onCopyLink}
+            title="${t('link.copy')}" aria-label="${t('link.copy')}">
+            <${Icon} name="link" /></button>
+        `}
         ${onDownload && html`
           <button class="video-close ${dlBusy ? 'dl-active' : ''}" disabled=${dlBusy}
             onClick=${() => {