Unify button tooltips across the app (#972)

* feat(tooltip): 2s open delay and shared tooltipAttrs helper

Add a 2s hover open delay in TooltipPortal (single behaviour source) so
tooltips no longer flash on quick pointer passes; hiding stays immediate.
Add tooltipAttrs() to pair data-tooltip with a matching aria-label for
buttons touched in the unification work. Covered by Vitest.

* feat(tooltip): lower open delay to 1s

2s felt too long in testing; 1s gives the same anti-flash behaviour
without making intentional hovers wait.

* feat(tooltip): action tooltips on the artist overview

Add tooltips describing the action to Last.fm, Wikipedia, Play All,
Shuffle and Radio. Shuffle/Radio now show a tooltip on desktop too,
not just mobile. Strings added to all 9 locales.

* feat(tooltip): action tooltips on the album overview

Add tooltips describing the action to the desktop Play, Artist Bio and
Download (ZIP) buttons, matching the mobile layout. Strings added to all
9 locales.

* feat(tooltip): action tooltips on the All Albums toolbar

Add tooltips describing the action to the sort, year and genre filter
buttons. SortDropdown gains an optional tooltip prop; the year and genre
filter components carry their own, so the tooltips also appear on the
other browse pages that reuse them. Strings added to all 9 locales.

* feat(tooltip): action tooltips on song-list rows

Add Play and Add-to-queue tooltips to the per-row icons in SongRow, used
by the Tracks browse list, Search and Advanced Search. Also localizes the
aria-labels, which were hardcoded English. New common.addToQueue in all 9
locales.

* fix(tooltip): uniform tooltip placement on the Artists toolbar

The favourite and multi-select buttons forced tooltips below while the
view-mode buttons auto-flipped above, so the row looked inconsistent.
Pin the view-mode buttons below too, matching the rest of the row and the
Albums toolbar.

* feat(tooltip): clarify and align the Advanced Search scope row

Add a leading "Search in:" label and per-chip tooltips so the
All/Artists/Albums/Songs row reads as a scope limiter. Drop the forced
below-placement on the small star filter (used only here) so the
favourites chip flips with the others instead of sitting alone below.
Strings added to all 9 locales.

* docs(changelog): tooltip unification (#972)

src/components/tooltipAttrs.ts

@@ -0,0 +1,24 @@
+/**
+ * Pairs a tooltip with its accessible label so the two never drift apart.
+ *
+ * Spread onto any element that should show a hover tooltip rendered by
+ * `TooltipPortal`. The same already-translated string becomes both the
+ * `data-tooltip` (visual hover label) and the `aria-label` (screen readers).
+ *
+ *   <button {...tooltipAttrs(t('albums.sortTooltip'))} onClick={…}>
+ *
+ * `pos: 'bottom'` is a viewport-edge escape hatch only (forces the tooltip
+ * below the anchor instead of the default auto-flip) — do not use it on
+ * ordinary toolbar buttons. `wrap` enables multi-line wrapping.
+ */
+export function tooltipAttrs(
+  text: string,
+  opts?: { pos?: 'bottom'; wrap?: boolean },
+): Record<string, string> {
+  return {
+    'data-tooltip': text,
+    'aria-label': text,
+    ...(opts?.pos ? { 'data-tooltip-pos': opts.pos } : {}),
+    ...(opts?.wrap ? { 'data-tooltip-wrap': '' } : {}),
+  };
+}