feat: icon view toggle, failing filter, quality badges

List and Tiles are now icons rather than words, centred in their
buttons — Segmented takes a ReactNode label and an optional title.

The red "N failing" count in the sidebar is a button: click it to see
only the channels that failed to refresh, click again for all of them.
It clears itself once a refresh fixes everything, so the filter can
never strand you on an empty list.

The player states its quality as a badge instead of loose grey text,
and a downloaded video now says so too — "Downloaded · 1440p" — read
from the file itself. Quality is the short side, so a portrait Short
reads 1080p rather than 1920p, and it resets between videos so one
never inherits the previous one's number.

src/components/TopBar.tsx

@@ -123,8 +123,27 @@ export default function TopBar({
           value={view}
           onChange={onView}
           options={[
-            { value: "list", label: "List" },
-            { value: "grid", label: "Tiles" },
+            {
+              value: "list",
+              title: "List",
+              label: (
+                <svg viewBox="0 0 24 24" className="size-4" fill="none" stroke="currentColor" strokeWidth="2">
+                  <path strokeLinecap="round" d="M4 6h16M4 12h16M4 18h16" />
+                </svg>
+              ),
+            },
+            {
+              value: "grid",
+              title: "Tiles",
+              label: (
+                <svg viewBox="0 0 24 24" className="size-4" fill="none" stroke="currentColor" strokeWidth="2">
+                  <rect x="4" y="4" width="7" height="7" rx="1.5" />
+                  <rect x="13" y="4" width="7" height="7" rx="1.5" />
+                  <rect x="4" y="13" width="7" height="7" rx="1.5" />
+                  <rect x="13" y="13" width="7" height="7" rx="1.5" />
+                </svg>
+              ),
+            },
           ]}
         />