feat(labs): visual polish wave — LabFX foundation + 33 sims juiced up

ФУНДАМЕНТ (4 новых файла):
- _fx_core.js: LabFX namespace, glow.drawGlow, glow.pulse, haptic, shake
- _fx_particles.js: пул 1500 объектов, 6 shapes (dot/spark/ring/smoke/splash/dust)
- _fx_motion.js: tween + 12 easings + critically-damped spring
- _fx_sound.js: 9 procedural synth-звуков (click/tick/whoosh/chime/fizz/spark/bounce/pour/drone), Web Audio API
- Sound toggle в шапке lab.html с localStorage-persist

UX МИКРО (CSS + JS):
- Button states: hover scale+brightness, active scale-down, disabled grayscale
- Slider polish: custom thumb с тенью, filled-track gradient, hover/active
- Focus rings через :focus-visible
- Tooltip system .tt-host data-tt= с 400ms hover, fade-in
- Marching ants для selection
- Loading skeleton с shimmer
- Empty state .sim-empty-* паттерн
- Toast: progress bar внизу, icons по типу
- Cursor states utility classes
- View Transitions API для smooth sim-switch, fallback на CSS fade

PHASE 2 — визуальные эффекты для 33 симуляций:

Physics motion: projectile (launch whoosh + landing splash/shake/haptic + target chime), pendulum (max-extension tick + bob glow), collision (bounce + sparks + shake), angrybirds (whoosh/bounce/fizz/chime + confetti), newton (rocket flame trail + scene transitions), forcesandbox (spring glow + impact sparks)

Physics fields: emfield (field-lines glow + particle trail + lightning при high field + Gauss-drag haptic + rod motion sparks), circuit (energized-wire glow ∝ current + LED bloom + short-circuit shake/spark + heat shimmer smoke + place/erase/switch sounds), opticsbench (beam glow на всех режимах + caustics dust у фокуса + TIR/Brewster one-shot sounds)

Thermo+waves: waves (mode-switch whoosh + Mach-cone particles + spectrum harmonic chime + waveform glow), hydrostatics (pour sound + splash при погружении + valve click), isoprocess (PV-trail dust), heatengine (drone цикла + hot/cold reservoir smoke/dust + phase-change ticks), radioactive (Geiger tick throttle + decay sparks + half-life chime + α/β/γ glow)

Chemistry: chemsandbox (pour splash + fizz bubbles/dust/spark по типу реакции + shake при горении), equilibrium/electrolysis/reactions/titration/flask/ionexchange/redox (pour/fizz/spark/chime по событиям, частицы при ключевых моментах), stoichiometry (fizz bubbles + recipe-change click)

Math+geom: geometry (tool-click + object-create tick + locus glow + challenge confetti via LabFX + haptic), triangle (vertex-drop tick + special-point glow), stereo (figure-change whoosh + cross-section chime, no particles — Three.js), trigcircle (drag-haptic + pitch∝angle tick + sin/cos glow), graph/graphtransform/quadratic (slider-tick throttled + curve glow + discriminant-cross chime), probability (bounce + finish-chime burst), normaldist (pulsing shade + bell glow)

Bio+misc: celldivision (phase-change whoosh + prophase dust + anaphase poles spark + cytokinesis chime), photosynthesis (photon tick + ATP chime + glucose sparkle), bohratom (electron-jump chime ∝ levels + photon spark), orbitals/crystal (mode-change whoosh — Three.js, sound only), logic (gate-place + wire-connect + LED bloom + HIGH wire flowing dots + preset chime), gas/brownian/diffusion/states (preset whoosh, throttled tick по событиям)

Все LabFX вызовы обёрнуты в if (window.LabFX) guard — graceful degradation если фундамент не загружен. 47 JS файлов прошли syntax check.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/js/labs/quadratic.js

@@ -14,6 +14,7 @@ class QuadraticSim {
     this.a = 1;
     this.b = 0;
     this.c = -1;
+    this._lastDSign = Math.sign(1 * 1 * 1 - 4 * 1 * (-1)); // track discriminant sign
 
     /* view */
     this.ox  = 0;
@@ -100,6 +101,14 @@ class QuadraticSim {
 
   _emit() {
     if (this.onUpdate) this.onUpdate(this.info());
+    if (window.LabFX) {
+      const D = this.b * this.b - 4 * this.a * this.c;
+      const sign = Math.sign(D);
+      if (sign !== this._lastDSign) {
+        this._lastDSign = sign;
+        LabFX.sound.play('chime', { pitch: 1.3 });
+      }
+    }
   }
 
   /* ── coordinate transforms ─────────────────────────── */
@@ -310,10 +319,18 @@ class QuadraticSim {
         const [rpx, rpy] = this._toPx(rx, 0);
         if (rpx < -20 || rpx > W + 20) continue;
 
-        // root dot
-        ctx.fillStyle = '#EF476F';
-        ctx.beginPath(); ctx.arc(rpx, rpy, 5.5, 0, Math.PI * 2); ctx.fill();
-        ctx.strokeStyle = 'rgba(255,255,255,0.8)'; ctx.lineWidth = 1.5; ctx.stroke();
+        // root dot with glow
+        if (window.LabFX) {
+          LabFX.glow.drawGlow(ctx, () => {
+            ctx.fillStyle = '#EF476F';
+            ctx.beginPath(); ctx.arc(rpx, rpy, 5.5, 0, Math.PI * 2); ctx.fill();
+            ctx.strokeStyle = 'rgba(255,255,255,0.8)'; ctx.lineWidth = 1.5; ctx.stroke();
+          }, { color: '#F59E0B', intensity: 8 });
+        } else {
+          ctx.fillStyle = '#EF476F';
+          ctx.beginPath(); ctx.arc(rpx, rpy, 5.5, 0, Math.PI * 2); ctx.fill();
+          ctx.strokeStyle = 'rgba(255,255,255,0.8)'; ctx.lineWidth = 1.5; ctx.stroke();
+        }
 
         // label
         ctx.fillStyle = '#EF476F';
@@ -450,10 +467,16 @@ class QuadraticSim {
     }));
   }
 
+  let _quadSoundTs = 0;
   function quadParam(name, val) {
     const v = parseFloat(val);
     document.getElementById('quad-' + name + '-val').textContent = v % 1 === 0 ? v : v.toFixed(1);
     if (quadSim) quadSim.setParams({ [name]: v });
+    const now = performance.now();
+    if (window.LabFX && now - _quadSoundTs > 80) {
+      _quadSoundTs = now;
+      LabFX.sound.play('tick', { volume: 0.1 });
+    }
   }
 
   function quadPreset(a, b, c) {