Files like Finder, richer mini player, in-app Back/Forward, Audio tab renamed Audiobooks

- Files: multi-select, batch move/copy/delete, rename checks, sort, filter, shortcuts, drag in (files and folders) to upload with progress and retries, drag to move, drag a file out to download
- Mini player: previous, seek bar with buffered range, time, shuffle/repeat, buffering spinner, swipe for next/previous, close
- Back/Forward bar that knows what history is possible
- Audio tab is now Audiobooks

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

public/style.css

@@ -169,8 +169,19 @@ input[type=search] { width: 100%; min-height: 44px; padding: 0 14px; border-radi
 .ibtn:active { background: var(--panel2); }
 .ibtn.big { width: 64px; height: 64px; background: var(--accent); color: var(--accent-t); }
 .ibtn.big svg { width: 30px; height: 30px; }
-.mini .bar2 { position: absolute; left: 0; right: 0; top: 0; height: 2px; background: var(--line); }
-.mini .bar2 i { display: block; height: 100%; background: var(--accent); width: 0; }
+.mini .bar2 { position: absolute; left: 0; right: 0; top: 0; height: 4px; background: var(--line); cursor: pointer; touch-action: none; }
+.mini .bar2::before { content: ''; position: absolute; left: 0; right: 0; top: -10px; bottom: -8px; } /* a taller area to grab */
+.mini .bar2 u { position: absolute; left: 0; top: 0; bottom: 0; width: 0; background: var(--muted); opacity: .45; }
+.mini .bar2 i { position: absolute; left: 0; top: 0; bottom: 0; background: var(--accent); width: 0; }
+.mini .mtime { color: var(--muted); font-size: 13px; font-variant-numeric: tabular-nums; display: none; }
+.mini .wide-only { display: none; }
+.mini .ibtn.on { color: var(--accent); }
+.mini .ibtn { position: relative; flex: none; }
+.mini .ibtn[data-r="1"]::after { content: '1'; position: absolute; font-size: 10px; font-weight: 700; right: 8px; bottom: 6px; }
+.mini { touch-action: pan-y; }
+@media (min-width: 768px) { .mini .mtime { display: block; } .mini .wide-only { display: grid; } .mini .bar2 { height: 5px; } }
+svg .spin, .spin { transform-origin: 12px 12px; animation: sp .8s linear infinite; }
+@keyframes sp { to { transform: rotate(360deg); } }
 .np { text-align: center; }
 .np .art { width: min(72vw, 300px); aspect-ratio: 1; border-radius: 16px; object-fit: cover; background: var(--panel2); margin: 8px auto 16px; display: block; }
 .np input[type=range] { width: 100%; accent-color: var(--accent); }
@@ -260,3 +271,33 @@ input, textarea, [contenteditable], .sheet p, .card p, #view .sub { -webkit-user
 .np .ibtn.on { color: var(--accent); }
 .np .ibtn[data-r="1"]::after { content: '1'; position: absolute; font-size: 10px; font-weight: 700; margin: 0 0 -14px 14px; }
 .np .ibtn { position: relative; }
+
+/* Files: selection, drag and drop, upload progress */
+.selbar { position: sticky; top: 0; z-index: 3; background: var(--bg); padding-bottom: 4px; }
+.selbar .bar { margin: 0 0 8px; align-items: center; }
+.selbar .selcount { margin-right: auto; }
+.selbar .bar { gap: 6px; }
+.selbar .btn { padding-left: 10px; padding-right: 10px; }
+.row.fr { cursor: default; }
+.row.fr.sel { background: var(--panel2); }
+.row .ck { width: 24px; height: 24px; border-radius: 50%; border: 2px solid var(--line); display: grid; place-items: center; flex: none; margin-left: 4px; }
+.row .ck.on { background: var(--accent); border-color: var(--accent); color: var(--accent-t); }
+.row .ck svg { width: 14px; height: 14px; }
+.dropt { outline: 2px dashed var(--accent); outline-offset: -2px; background: var(--panel2); }
+#fmain.dropt { border-radius: 16px; }
+#upbar { position: fixed; z-index: 15; left: 50%; transform: translateX(-50%); top: calc(var(--sat) + 10px); width: min(520px, calc(100vw - 24px)); display: flex; align-items: center; gap: 8px;
+  background: var(--panel); border: 1px solid var(--line); border-radius: 14px; padding: 10px 12px; box-shadow: 0 8px 28px rgba(0,0,0,.25); }
+#upbar .upm { flex: 1; min-width: 0; position: relative; padding-bottom: 6px; }
+#upbar .upm b, #upbar .upm small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+#upbar .upm small { color: var(--muted); }
+#upbar .upm i { position: absolute; left: 0; bottom: 0; height: 3px; border-radius: 2px; background: var(--accent); transition: width .2s; }
+#fmain { min-height: 240px; }
+
+/* Back / Forward bar */
+#navbar { display: flex; align-items: center; gap: 2px; padding: calc(var(--sat) + 4px) calc(var(--sar) + 8px) 0 calc(var(--sal) + 8px); }
+#navbar[hidden], body.editing #navbar { display: none; }
+#navbar .ibtn { width: 40px; height: 40px; }
+#navbar .ibtn:disabled { opacity: .3; cursor: default; }
+#navbar #nvt { color: var(--muted); font-size: 13px; margin-left: 6px; }
+body:not(.editing) #view { padding-top: 8px; }
+@media (min-width: 768px) { #navbar { padding-left: 24px; } body:not(.editing) #view { padding-top: 12px; } }