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, 8 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/style.css b/packages/meshbay-hub/src/meshbay_hub/static/style.css
index 9383043..bde1c61 100644
--- a/packages/meshbay-hub/src/meshbay_hub/static/style.css
+++ b/packages/meshbay-hub/src/meshbay_hub/static/style.css
@@ -5613,6 +5613,14 @@ h2 .gn-owner, h3 .gn-owner { font-size: 0.55em; }
   overflow: hidden;
   text-overflow: ellipsis;
 }
+/* The same note for "Copy link" (copy-link.js). When the clipboard refused, it
+   carries the link itself, which must be readable whole rather than cut. */
+.copy-link-note.playlist-note {
+  white-space: normal;
+  overflow-wrap: anywhere;
+  border-radius: 12px;
+  text-align: center;
+}
 
 /* A run of single-album artists, pooled into one grid so five of them fill one
    row instead of spending five (music-app.js `albumSections`).