fix(labs): SVG markup rendered as text in 6 simulations

Hardcoded inline <svg class="ic"> markers used as arrow replacements

(left over from emoji removal) were displayed as raw HTML text where

the consumer used textContent or canvas fillText:

- chemsandbox: csbar-v5 (Продукты cell) used textContent → SVG visible.

  Switched to innerHTML for consistency with eq/ionNet cells.

  Quiz question (qEl.textContent) and answer also receiving SVG —

  cleaned via _csClean at source.

- reactions: modeTxt drawn via canvas fillText — replaced SVG with →.

- ionexchange: REACTIONS data + canvas labels — bulk SVG → Unicode arrows.

- newton: action button labels used textContent → switched to innerHTML;

  canvas arrow labels: SVG → Unicode →/↓.

- collision: 'KE сохранена' canvas label — SVG checkmark → ✓.

- projectile: canvas badges + textContent wind label — SVG → Unicode ←/→/↩.

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

frontend/js/labs/projectile.js

@@ -147,8 +147,8 @@ class ProjectileSim {
       }
     }
     const st = this.stats();
-    const windStr = this.wind !== 0 ? ` <svg class="ic" viewBox="0 0 24 24"><path d="M17.7 7.7a2.5 2.5 0 1 1 1.8 4.3H2"/><path d="M9.6 4.6A2 2 0 1 1 11 8H2"/><path d="M12.6 19.4A2 2 0 1 0 14 16H2"/></svg>${this.wind > 0 ? '+' : ''}${this.wind}` : '';
-    const label = `${this.angle}° ${this.v0}м/с${windStr}${this.drag ? ' +drag' : ''}${this.bounce ? ' <svg class="ic" viewBox="0 0 24 24"><polyline points="9 14 4 9 9 4"/><path d="M20 20v-7a4 4 0 0 0-4-4H4"/></svg>' : ''}`;
+    const windStr = this.wind !== 0 ? ` ветер ${this.wind > 0 ? '+' : ''}${this.wind}` : '';
+    const label = `${this.angle}° ${this.v0}м/с${windStr}${this.drag ? ' +drag' : ''}${this.bounce ? ' ↩' : ''}`;
     const color = this._GHOST_COLORS[this._ghostIdx % this._GHOST_COLORS.length];
     this._ghostIdx++;
     this._ghosts.push({ points, color, label, range: st.range, hMax: st.hMax });
@@ -811,12 +811,12 @@ class ProjectileSim {
       bRight -= 130;
     }
     if (this.wind !== 0) {
-      const dir = this.wind > 0 ? '<svg class="ic" viewBox="0 0 24 24"><line x1="5" y1="12" x2="19" y2="12"/><polyline points="12 5 19 12 12 19"/></svg>' : '<svg class="ic" viewBox="0 0 24 24"><line x1="19" y1="12" x2="5" y2="12"/><polyline points="12 19 5 12 12 5"/></svg>';
+      const dir = this.wind > 0 ? '→' : '←';
       this._drawBadge(ctx, bRight, PT + 6, dir + ' ветер ' + Math.abs(this.wind) + 'м/с', 'rgba(6,214,224,.12)', 'rgba(6,214,224,.8)');
       bRight -= 130;
     }
     if (this.bounce) {
-      this._drawBadge(ctx, bRight, PT + 6, '<svg class="ic" viewBox="0 0 24 24"><polyline points="9 14 4 9 9 4"/><path d="M20 20v-7a4 4 0 0 0-4-4H4"/></svg> e=' + this.restitution.toFixed(2), 'rgba(123,245,164,.1)', 'rgba(123,245,164,.75)');
+      this._drawBadge(ctx, bRight, PT + 6, '↩ e=' + this.restitution.toFixed(2), 'rgba(123,245,164,.1)', 'rgba(123,245,164,.75)');
     }
 
     /* speed badge bottom-right */
@@ -1077,7 +1077,7 @@ function _projArrow(ctx, x1, y1, x2, y2, color, lw) {
         pSim.onPlayPause = projPlayPause;
       }
       pSim.fit();
-      projParam();       // sync sliders <svg class="ic" viewBox="0 0 24 24"><line x1="5" y1="12" x2="19" y2="12"/><polyline points="12 5 19 12 12 19"/></svg> sim
+      projParam();       // sync sliders → sim
       pSim.draw();
       _projUpdateUI(pSim.stats());
     }));
@@ -1187,7 +1187,7 @@ function _projArrow(ctx, x1, y1, x2, y2, color, lw) {
 
   function projWindChange() {
     const wind = +document.getElementById('sl-wind').value;
-    const label = wind === 0 ? '0 м/с' : (wind > 0 ? '<svg class="ic" viewBox="0 0 24 24"><line x1="5" y1="12" x2="19" y2="12"/><polyline points="12 5 19 12 12 19"/></svg> +' : '<svg class="ic" viewBox="0 0 24 24"><line x1="19" y1="12" x2="5" y2="12"/><polyline points="12 19 5 12 12 5"/></svg> ') + Math.abs(wind) + ' м/с';
+    const label = wind === 0 ? '0 м/с' : (wind > 0 ? '→ +' : '← ') + Math.abs(wind) + ' м/с';
     document.getElementById('p-wind').textContent = label;
     document.getElementById('ps-loss-wrap').style.display = wind !== 0 ? '' : (pSim && pSim.drag ? '' : 'none');
     if (pSim) { pSim.setParams({ wind }); _projSyncPlayBtn(); }