refactor: distribute lab-init.js into 34 engine files

lab-init.js: 4098 -> 543 lines (infrastructure + THEORY only)

Each sim's _open*() + UI helpers moved to its engine file:
graph.js, projectile.js, collision.js, magnetic.js, triangle.js,
geometry.js, trigcircle.js, gas.js (molphys), coulomb.js, circuit.js,
reactions.js (chemistry), newton.js (dynamics), chemsandbox.js,
celldivision.js, photosynthesis.js, angrybirds.js, quadratic.js,
normaldist.js, graphtransform.js, pendulum.js, equilibrium.js,
thinlens.js, mirror.js, isoprocess.js, titration.js, refraction.js,
probability.js, bohratom.js, electrolysis.js, waves.js,
crystal.js, orbitals.js, stereo.js, hydrostatics.js

All 34 engine files syntax-checked OK.

frontend/js/labs/electrolysis.js

@@ -1,4 +1,4 @@
-'use strict';
+'use strict';
 /**
  * ElectrolysisSim v2 — Электролиз водных растворов
  * Закон Фарадея: m = M·I·t / (n·F),  F = 96485 Кл/моль
@@ -539,3 +539,45 @@ class ElectrolysisSim {
 }
 
 if (typeof module !== 'undefined') module.exports = ElectrolysisSim;
+
+/* ─── lab UI init ─────────────────────────────────── */
+  function _openElectrolysis() {
+    document.getElementById('sim-topbar-title').textContent = 'Электролиз';
+    _simShow('sim-electrolysis');
+    _registerSimState('electrolysis', () => elecSim?.getParams(), st => elecSim?.setParams(st));
+    if (_embedMode) _startStateEmit('electrolysis');
+    requestAnimationFrame(() => requestAnimationFrame(() => {
+      if (!elecSim) {
+        elecSim = new ElectrolysisSim(document.getElementById('electrolysis-canvas'));
+        elecSim.onUpdate = _elecUpdateUI;
+      }
+      elecSim.fit();
+      elecSim.reset();
+      elecSim.play();
+    }));
+  }
+
+  function elecParam(name, val) {
+    const v = parseFloat(val);
+    if (name === 'voltage') document.getElementById('elec-V-val').textContent = v;
+    if (elecSim) elecSim.setParams({ [name]: v });
+  }
+
+  function elecPreset(name, btn) {
+    document.querySelectorAll('.elec-type-btn').forEach(b => b.classList.remove('active'));
+    if (btn) btn.classList.add('active');
+    const voltages = { nacl: 6, cuso4: 4, h2so4: 3 };
+    const vt = voltages[name] || 6;
+    document.getElementById('sl-elec-V').value = vt; document.getElementById('elec-V-val').textContent = vt;
+    if (elecSim) { elecSim.setParams({ electrolyte: name, voltage: vt }); elecSim.reset(); elecSim.play(); }
+  }
+
+  function _elecUpdateUI(info) {
+    const v = (id, val) => { const el = document.getElementById(id); if (el) el.textContent = val; };
+    v('elecbar-v1', typeof info.current === 'number' ? info.current.toFixed(2) : '—');
+    v('elecbar-v2', typeof info.massDeposited === 'number' ? info.massDeposited.toFixed(3) + ' г' : '—');
+    v('elecbar-v3', typeof info.gasVolume === 'number' ? info.gasVolume.toFixed(1) : '—');
+    v('elecbar-v4', typeof info.time === 'number' ? info.time.toFixed(0) + ' с' : '—');
+  }
+
+  /* ── waves ── */