fix(queue): name the queue header's two older actions

Clear queue and Add queue to playlist were named by a `title` attribute
and nothing else, while the close button beside them has carried an
`aria-label` since #24. They get one too.

`title` is a name, so this is the weak-name case rather than the missing
one: it is the *last* fallback in the accname order, so any content put
inside the button later silently outranks it, and a phone has no hover
to show it. The `title`s stay — on a desktop they are also the tooltip
for an icon-only control, which is a different job.

The assertion is the part worth reading. The obvious spec — `getByRole`
by name, which is what `queue-overlay.spec.ts` already does for the
close button — is **green on the broken build**: measured against the
running pre-fix app, both buttons matched. So the second test states the
property as what it is, that the name is not the tooltip: it removes the
`title` attributes and asks again, which was 0 and 0 on main and is 1
and 1 now.

Closes #170

frontend/src/components/queue-panel/queue-panel.ts

@@ -2201,11 +2201,25 @@ export class QueuePanel
                             `
                             : nothing}
                     </div>
+                    <!-- **Every action here is named by aria-label**, like
+                         the close button #24 added beside them (#170). A
+                         title alone *is* a name, which is why a sweep for
+                         empty names reports these clean and why an
+                         assertion by role and name is green either way --
+                         but it is the weakest one: title is the last
+                         fallback in the accname order, so any content put
+                         inside the button later silently outranks it, and
+                         a phone has no hover to show it as a tooltip.
+
+                         The titles stay. On a desktop they are the tooltip
+                         for an icon-only control, which is a different job
+                         from naming it, and aria-label does not do it. -->
                     <div class="header-actions">
                         <button
                             class="header-action-button"
                             @click=${() => void this.handleClearQueue()}
                             ?disabled=${tracks.length === 0}
+                            aria-label="Clear queue"
                             title="Clear queue"
                         >
                             <wa-icon
@@ -2216,6 +2230,7 @@ export class QueuePanel
                             class="header-action-button add-to-playlist-button"
                             @click=${this.handleAddToPlaylist}
                             ?disabled=${tracks.length === 0}
+                            aria-label="Add queue to playlist"
                             title="Add queue to playlist"
                         >
                             <wa-icon