feat: redesign mass exercise icons and update search-sdf

- fragmentation: propylbenzene alpha-beta cleavage with correct 120° angles
  at ring-chain junction (radial substituent bond), aromatic circle, •+ label
- exact-mass: reuse isotope-distribution peaks with crosshair target on M peak
- mf-info: renamed from ms-info, curved J-arrow from MF to spectrum
- search-sdf: updated to match standard magnifier geometry with text element
- Remove electron-ionization icon

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: lpatiny

docs/index.html

@@ -378,12 +378,48 @@
 </div>            
 
 
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-charge"></span>
+	<span>mass-charge</span>
+</div>            
+            
+
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-exact-mass"></span>
+	<span>mass-exact-mass</span>
+</div>            
+            
+
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-find-mf"></span>
+	<span>mass-find-mf</span>
+</div>            
+            
+
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-fragmentation"></span>
+	<span>mass-fragmentation</span>
+</div>            
+            
+
 <div class="preview" style="font-size: 12px">
 	<span class="preview_icon ci-icon ci-icon-mass-impurities"></span>
 	<span>mass-impurities</span>
 </div>            
 
 
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-isotope-distribution"></span>
+	<span>mass-isotope-distribution</span>
+</div>            
+            
+
+<div class="preview" style="font-size: 12px">
+	<span class="preview_icon ci-icon ci-icon-mass-mf-info"></span>
+	<span>mass-mf-info</span>
+</div>            
+            
+
 <div class="preview" style="font-size: 12px">
 	<span class="preview_icon ci-icon ci-icon-mass-monoisotopic"></span>
 	<span>mass-monoisotopic</span>