fix(ui): restore round play and enqueue buttons on cards and rails (#788)

Album-card play and enqueue overlay buttons revert to a pill shape
(var(--radius-full)); the small play button next to track numbers in
the album track list / artist top-tracks reverts to a circle (50%).
The square shape from the consistency sweep felt off against the round
covers — back to the original round/pill family for these specific
icons. All other surfaces touched in #745 stay on var(--radius-sm).

src/styles/components/album-row-container.css

@@ -236,7 +236,7 @@
   color: var(--ctp-crust);
   border: none;
   padding: 8px 20px;
-  border-radius: var(--radius-sm);
+  border-radius: var(--radius-full);
   display: flex;
   align-items: center;
   justify-content: center;

src/styles/components/tracklist.css

@@ -269,7 +269,7 @@
   height: 24px;
   padding: 0;
   border: none;
-  border-radius: var(--radius-sm);
+  border-radius: 50%;
   background: var(--accent);
   color: var(--ctp-crust);
   cursor: pointer;