fix(player): redesign cleanup pass — sleeve, tonearm, AGC, dead code

Production-readiness pass before merging the Studio Reference redesign
to master.

Audio (backend):
- Reset AGC `_spectrum_ref` envelope on `start()` so a long silent gap
  between sessions doesn't make the first new transients clip at the
  ceiling. Annotated the trade-off (loud transient lifts reference for
  a few seconds afterwards — the price of real loudness).
- Add `tests/test_audio_analyzer.py` with 10 cases: bin-edge layout,
  AGC attack/release asymmetry, lifecycle reset. Skips numpy-dependent
  cases when numpy isn't installed; CI has it.

Vinyl mode dead code removed:
- The toggle button was dropped during the sleeve refactor but the JS
  state, 2 s `setInterval`, `beforeunload` handler, and `applyVinylMode`
  call (commented out in app.js) all stayed. Now properly excised from
  player.js + app.js + window.* exports.
- Stripped the matching `.album-art-container.vinyl*` CSS block and its
  `vinylSpin` keyframes (~95 LoC).

Sleeve + tonearm fixes:
- Removed the duplicate `.now-playing .vinyl-stage` / `.vinyl-label` /
  `.tonearm` block that was overriding the new `.vinyl-stage` rules by
  source order — the uncommitted tonearm geometry never took effect
  because the stale clone won the cascade.
- Tightened tonearm to 36% × 36% at right:-6%, top:26% so the SVG
  bounding box stays right of the sleeve (sleeve right edge ~68%).
  Needle now lands on the visible disc grooves at both rest and
  playing rotations and never overlaps the cover.
- Removed sleeve `transform: rotate(-2.5deg)` + the matching mobile
  `-1.8deg` override; sleeve now sits flat and squared-off.
- Removed the 1px inset hairline on the sleeve and the 1px outline +
  inset highlight on the album art — cleaner, no semitransparent
  border noise.
- Album art inset 5% to expose a cardstock margin around the print
  (using explicit width/height — `inset` shorthand triggered the CSS
  replaced-element rule that uses the image's intrinsic size and blew
  out the grid track).

Mobile + misc:
- Removed mobile tonearm overrides at 720px and 420px — they were
  calibrated for the pre-sleeve geometry and put the needle back over
  the cover on phones; desktop geometry is proportional and works.
- Added `<meta name="mobile-web-app-capable">` alongside the legacy
  Apple variant to silence the deprecation warning in Chromium.
- Replaced the "PRIMARY" badge on display cards with a copper star
  icon (translation key still drives title + aria-label).
- `.gitattributes` with `* text=auto eol=lf` so Windows checkouts stop
  nagging "LF will be replaced by CRLF".

Annotations:
- "REF · 24" record-label catalogue mark marked as intentional non-i18n
  decoration in index.html.

CI: ruff clean, pytest 7 passed + 3 numpy-skipped (all 10 run on CI).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

media_server/static/js/player.js

@@ -208,72 +208,6 @@ document.addEventListener('click', (e) => {
     }
 });
 
-// Vinyl mode
-let vinylMode = localStorage.getItem('vinylMode') === 'true';
-
-function getVinylAngle() {
-    const art = document.getElementById('album-art');
-    if (!art) return 0;
-    const st = getComputedStyle(art);
-    const tr = st.transform;
-    if (!tr || tr === 'none') return 0;
-    const m = tr.match(/matrix\((.+)\)/);
-    if (!m) return 0;
-    const vals = m[1].split(',').map(Number);
-    const angle = Math.round(Math.atan2(vals[1], vals[0]) * (180 / Math.PI));
-    return ((angle % 360) + 360) % 360;
-}
-
-function saveVinylAngle() {
-    if (!vinylMode) return;
-    localStorage.setItem('vinylAngle', getVinylAngle());
-}
-
-function restoreVinylAngle() {
-    const saved = localStorage.getItem('vinylAngle');
-    if (saved) {
-        const art = document.getElementById('album-art');
-        if (art) art.style.setProperty('--vinyl-offset', `${saved}deg`);
-    }
-}
-
-setInterval(saveVinylAngle, 2000);
-window.addEventListener('beforeunload', saveVinylAngle);
-
-export function toggleVinylMode() {
-    if (vinylMode) saveVinylAngle();
-    vinylMode = !vinylMode;
-    localStorage.setItem('vinylMode', vinylMode);
-    applyVinylMode();
-}
-
-export function applyVinylMode() {
-    const container = document.querySelector('.album-art-container');
-    const btn = document.getElementById('vinylToggle');
-    if (!container) return;
-    if (vinylMode) {
-        container.classList.add('vinyl');
-        if (btn) btn.classList.add('active');
-        restoreVinylAngle();
-        updateVinylSpin();
-    } else {
-        saveVinylAngle();
-        container.classList.remove('vinyl', 'spinning', 'paused');
-        if (btn) btn.classList.remove('active');
-    }
-}
-
-function updateVinylSpin() {
-    const container = document.querySelector('.album-art-container');
-    if (!container || !vinylMode) return;
-    container.classList.remove('spinning', 'paused');
-    if (currentPlayState === 'playing') {
-        container.classList.add('spinning');
-    } else if (currentPlayState === 'paused') {
-        container.classList.add('paused');
-    }
-}
-
 // Audio Visualizer
 export let visualizerEnabled = localStorage.getItem('visualizerEnabled') === 'true';
 export let visualizerAvailable = false;
@@ -361,13 +295,6 @@ export function stopVisualizerRender() {
     if (visualizerCtx && canvas) {
         visualizerCtx.clearRect(0, 0, canvas.width, canvas.height);
     }
-    const art = document.getElementById('album-art');
-    if (art) {
-        art.style.transform = '';
-        art.style.removeProperty('--vinyl-scale');
-    }
-    const glow = document.getElementById('album-art-glow');
-    if (glow) glow.style.opacity = '';
     frequencyData = null;
     smoothedFrequencies = null;
     document.body.classList.remove('audio-spectrum-live');
@@ -417,20 +344,9 @@ function renderVisualizerFrame() {
         visualizerCtx.fill();
     }
 
-    const bass = frequencyData.bass || 0;
-    const scale = 1 + bass * 0.04;
-    const art = document.getElementById('album-art');
-    if (art) {
-        if (vinylMode) {
-            art.style.setProperty('--vinyl-scale', scale);
-        } else {
-            art.style.transform = `scale(${scale})`;
-        }
-    }
-    const glow = document.getElementById('album-art-glow');
-    if (glow) {
-        glow.style.opacity = (0.4 + bass * 0.4).toFixed(2);
-    }
+    // Bass-driven album-art scale + glow pulse removed — the
+    // "burst" looked unnatural on the sleeve. Spectrum bars +
+    // VU needle remain the audio-reactive elements.
 
     // Drive the editorial .spectrum bars from the same frequency data.
     updateEditorialSpectrum(smoothedFrequencies, numBins);
@@ -464,10 +380,12 @@ function updateEditorialSpectrum(bins, numBins) {
         for (let j = startIdx; j < endIdx && j < numBins; j++) {
             if (bins[j] > peak) peak = bins[j];
         }
-        // Per-bar high-end gain: 1.0 at the lowest bar, ~3.0 at the highest.
-        const gain = 1 + (i / barCount) * 2.0;
+        // Per-bar high-end gain: 1.0 at the lowest bar, ~1.8 at the highest.
+        // Backend now ships AGC-normalized bins (peak ~1, transients up to 1.5)
+        // so the master multiplier stays modest to avoid perma-clipping.
+        const gain = 1 + (i / barCount) * 0.8;
         // Floor at 12% so silent bars are still visually present.
-        const pct = Math.max(12, Math.min(100, peak * 110 * gain));
+        const pct = Math.max(12, Math.min(100, peak * 65 * gain));
         bars[i].style.height = pct + '%';
     }
 }
@@ -898,7 +816,6 @@ export function updatePlaybackState(state) {
             dom.playPauseIcon.innerHTML = SVG_PLAY;
             dom.miniPlayPauseIcon.innerHTML = SVG_PLAY;
     }
-    updateVinylSpin();
 }
 
 function updateProgress(position, duration) {