feat(desktop): promote Copy link to the message hover action bar

desktop/src/features/messages/ui/MessageActionBar.tsx

@@ -53,6 +53,32 @@ import { Tooltip, TooltipContent, TooltipTrigger } from "@/shared/ui/tooltip";
 const ACTION_BUTTON_CLASS = "h-8 w-8 rounded-full p-0";
 const ACTION_ICON_CLASS = "!h-4 !w-4";
 
+/** Copying a message link is offered from both the hover action bar and the
+ *  More menu; both paths share this exact link-building + toast behavior. */
+function copyMessageLink(channelId: string, message: TimelineMessage) {
+  const { rootId } = getThreadReference(message.tags ?? []);
+  const link = buildMessageLink({
+    channelId,
+    messageId: message.id,
+    threadRootId: rootId,
+  });
+  copyTextToClipboard(link, "Link copied to clipboard");
+}
+
+/** Gate shared by every copy-link surface: pending sends have no delivered
+ *  event to link to, huddle system rows aren't linkable, and callers without
+ *  a channelId (e.g. inbox preview rows) can't build the link. */
+function canCopyMessageLink(
+  message: TimelineMessage,
+  channelId: string | null | undefined,
+): channelId is string {
+  return (
+    !message.pending &&
+    message.kind !== KIND_HUDDLE_STARTED &&
+    Boolean(channelId)
+  );
+}
+
 function MoreActionsMenu({
   channelId,
   message,
@@ -242,17 +268,11 @@ function MoreActionsMenu({
             </DropdownMenuItem>
           ) : null}
 
-          {hasCopyActions && channelId ? (
+          {canCopyMessageLink(message, channelId) ? (
             <DropdownMenuItem
               data-testid={`copy-message-link-${message.id}`}
               onClick={() => {
-                const { rootId } = getThreadReference(message.tags ?? []);
-                const link = buildMessageLink({
-                  channelId,
-                  messageId: message.id,
-                  threadRootId: rootId,
-                });
-                copyTextToClipboard(link, "Link copied to clipboard");
+                copyMessageLink(channelId, message);
               }}
             >
               <Link2 className="h-4 w-4" />
@@ -566,6 +586,27 @@ export const MessageActionBar = React.memo(function MessageActionBar({
             </Tooltip>
           ) : null}
 
+          {canCopyMessageLink(message, channelId) ? (
+            <Tooltip>
+              <TooltipTrigger asChild>
+                <Button
+                  aria-label="Copy link"
+                  className={ACTION_BUTTON_CLASS}
+                  data-testid={`copy-link-message-${message.id}`}
+                  onClick={() => {
+                    copyMessageLink(channelId, message);
+                  }}
+                  size="sm"
+                  type="button"
+                  variant="ghost"
+                >
+                  <Link2 className={ACTION_ICON_CLASS} />
+                </Button>
+              </TooltipTrigger>
+              <TooltipContent>Copy link</TooltipContent>
+            </Tooltip>
+          ) : null}
+
           {hasMoreMenuActions ? (
             <MoreActionsMenu
               channelId={channelId}