android: hours on the library's count line, By format, Jump back in on the empty search

The desktop Library summary's hours on the phone's count line; a By format
order from the file stats (lossless by depth and rate first, then by
bitrate, the badge as the card's line); the empty Search page's Jump back
in — the last records played — as the desktop's empty search shows them.

src/mobile/HalfSheet.svelte

@@ -21,7 +21,7 @@
     import { note } from "./notice.svelte.js";
     import { fmtOf, albumFmt, fmtBytes, basename, dirname, longDur, mmss, titleFromName } from "./util.js";
 
-    const SORTS = [["added", "Recently added"], ["az", "A–Z"], ["artist", "By artist"], ["year", "By year"]];
+    const SORTS = [["added", "Recently added"], ["az", "A–Z"], ["artist", "By artist"], ["year", "By year"], ["format", "By format"]];
 
     /* the last sheet is kept through its slide down */
     let shown = $state(null);

src/mobile/screens/Library.svelte

@@ -18,7 +18,7 @@
     let { entry, screenEl = null } = $props();
 
     const TABS = [["albums", "Albums"], ["artists", "Artists"], ["tracks", "Tracks"], ["playlists", "Playlists"], ["gaps", "Gaps"]];
-    const SORTS = [["added", "Recently added"], ["az", "A–Z"], ["artist", "By artist"], ["year", "By year"]];
+    const SORTS = [["added", "Recently added"], ["az", "A–Z"], ["artist", "By artist"], ["year", "By year"], ["format", "By format"]];
 
     const tab = $derived(entry.c.tab || "albums");
     const sort = $derived(entry.c.sort || "added");
@@ -30,11 +30,25 @@
             if (sort === "az") return x.title.localeCompare(y.title);
             if (sort === "artist") return x.artist.localeCompare(y.artist) || (x.year || 0) - (y.year || 0);
             if (sort === "year") return (y.year || 0) - (x.year || 0) || y.added_at - x.added_at;
+            if (sort === "format") {
+                /* lossless first, then the higher bitrate, then the name */
+                const fx = fmtRank(lib.stats[x.id]);
+                const fy = fmtRank(lib.stats[y.id]);
+                return fy - fx || x.title.localeCompare(y.title);
+            }
             return y.added_at - x.added_at;
         });
         return l;
     });
     const totalTracks = $derived(lib.albums.reduce((n, a) => n + (a.track_count || 0), 0));
+    const totalSecs = $derived(Object.values(lib.stats).reduce((n, st) => n + (st.secs || 0), 0));
+    const hours = $derived(totalSecs >= 3600 ? Math.round(totalSecs / 3600) + " hours" : totalSecs ? Math.round(totalSecs / 60) + " min" : "");
+    /* By format: a number the sort can compare — lossless by depth and rate, lossy by bitrate */
+    function fmtRank(st) {
+        if (!st || !st.formats?.length) return 0;
+        if (st.bit_depth && st.sample_rate) return 1_000_000 + st.bit_depth * 1000 + Math.round(st.sample_rate / 1000);
+        return st.avg_kbps || 1;
+    }
     const arts = $derived(artists());
 
     /* ── Gaps — the desktop's (Library.svelte's gapSection): only a shelf
@@ -101,7 +115,7 @@
         {/each}
     </div>
     <div class="countline">
-        <span class="t-sub">{list.length} album{list.length === 1 ? "" : "s"} · {totalTracks} tracks</span>
+        <span class="t-sub">{list.length} album{list.length === 1 ? "" : "s"} · {totalTracks} tracks{hours ? " · " + hours : ""}</span>
         <button class="iconbtn sm muted" onclick={() => patch({ view: view === "grid" ? "list" : "grid" })} aria-label="Grid or list">
             <Icon name={view === "grid" ? "playlist" : "layers"} size={18} />
         </button>
@@ -111,7 +125,7 @@
     {:else if view === "grid"}
         <div class="grid2">
             {#each list as a (a.id)}
-                <Release title={a.title} sub={sort === "year" ? String(a.year || "") : a.artist} path={a.art_path} badge={statLabel(lib.stats[a.id]) || null} onclick={() => push("album", { id: a.id }, screenEl)} onmore={() => openHalf("album", { album: a })} />
+                <Release title={a.title} sub={sort === "year" ? String(a.year || "") : sort === "format" ? (statLabel(lib.stats[a.id]) || a.artist) : a.artist} path={a.art_path} badge={statLabel(lib.stats[a.id]) || null} onclick={() => push("album", { id: a.id }, screenEl)} onmore={() => openHalf("album", { album: a })} />
             {/each}
         </div>
     {:else}

src/mobile/screens/Search.svelte

@@ -292,6 +292,14 @@
         Artists, records and songs from the catalog; a song plays from the best copy the network has, a record opens its page.
         {#if !online}Sign in on Community to play what the library does not hold.{/if}
     </div>
+    {#if lib.recents.length}
+        <div class="sec"><h2>Jump back in <em>· picks up where you left off</em></h2></div>
+        <div class="rail">
+            {#each lib.recents.slice(0, 8) as r (r.album_id)}
+                <Release title={r.title} sub={r.artist} path={r.art_path} onclick={() => push("album", { id: r.album_id }, screenEl)} />
+            {/each}
+        </div>
+    {/if}
     {#if recents.length}
         <div class="sec"><h2>Recent</h2><button class="all" onclick={() => { recents = []; keepRecents(); }}>Clear</button></div>
         <div class="chips recent-chips" style="padding-bottom: 12px">