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, 67 insertions, 0 deletions

diff --git a/packages/meshbay-hub/src/meshbay_hub/static/copy-link.js b/packages/meshbay-hub/src/meshbay_hub/static/copy-link.js
new file mode 100644
index 0000000..ad6c3be
--- /dev/null
+++ b/packages/meshbay-hub/src/meshbay_hub/static/copy-link.js
@@ -0,0 +1,67 @@
+import { t } from './i18n.js';
+import * as platform from './platform.js';
+import { groupLinkRoute } from './group-link.js';
+
+/**
+ * "Copy link": the `#/name@owner/path` address of a file or folder
+ * (group-link.js), on this hub, put on the clipboard.
+ *
+ * The hub's origin, never the page's: in the desktop application the page is
+ * `app://meshbay`, and a link that only opens inside one person's application
+ * is not a link.
+ */
+
+/** The full link to `path` inside `group` (`{ name, owner_username }`). */
+export function groupItemLink(group, path) {
+  return platform.hubOrigin() + '/#' + groupLinkRoute(group, path);
+}
+
+/** An entry's path inside its group: its folder, root first, then its name. */
+export function entryPath(entry, dir = entry.path) {
+  return [dir, entry.name].filter(Boolean).join('/');
+}
+
+// The async clipboard first; the old command where it is refused — a page
+// without focus, a WebView without the permission. Neither needs to read
+// anything back.
+async function _write(text) {
+  try {
+    await navigator.clipboard.writeText(text);
+    return true;
+  } catch { /* fall through */ }
+  const area = document.createElement('textarea');
+  area.value = text;
+  area.setAttribute('readonly', '');
+  area.style.cssText = 'position:fixed;top:0;left:0;opacity:0;pointer-events:none';
+  document.body.appendChild(area);
+  area.select();
+  let ok = false;
+  try { ok = document.execCommand('copy'); } catch { ok = false; }
+  area.remove();
+  return ok;
+}
+
+let _note = null;
+let _noteTimer = null;
+
+// Said once and gone, in the playlists' note (style.css `.playlist-note`).
+// Appended to the body rather than rendered by a view, because the views that
+// copy include modals and a context menu that has already closed.
+function _say(text) {
+  if (!_note) {
+    _note = document.createElement('div');
+    _note.className = 'playlist-note copy-link-note';
+    _note.setAttribute('role', 'status');
+  }
+  _note.textContent = text;
+  document.body.appendChild(_note);
+  clearTimeout(_noteTimer);
+  _noteTimer = setTimeout(() => { if (_note) _note.remove(); }, 2500);
+}
+
+/** Copy `url`, and say whether it worked. The link itself is shown if not. */
+export async function copyLink(url) {
+  if (!url) return;
+  const ok = await _write(url);
+  _say(ok ? t('link.copied') : t('link.copy_failed', { url }));
+}