feat(fitness/measure): theme-adaptive waist svg

Replaces static PNG with currentColor-stroked SVG matching
forearm/thigh pattern for light/dark theme adaptation.

static/fitness/measure/waist.svg

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   width="36.257542mm"
+   height="39.737869mm"
+   viewBox="0 0 36.257542 39.737869"
+   version="1.1"
+   xmlns="http://www.w3.org/2000/svg">
+  <g fill="none" stroke="currentColor" stroke-width="1.32292" stroke-linecap="round" stroke-linejoin="round">
+    <path d="m 0.66145998,0.67347998 c 0,0 2.15638302,2.99555002 3.77590302,4.95587002 0.859507,1.04038 1.179969,1.15047 3.598907,1.29797 1.914122,0.11671 7.492809,0.059 7.492809,0.059" />
+    <path d="m 35.596079,0.66145998 c 0,0 -2.15638,2.99554002 -3.7759,4.95587002 -0.85951,1.04038 -1.17997,1.15047 -3.59891,1.29796 -1.91412,0.11672 -7.49281,0.059 -7.49281,0.059" />
+    <path d="m 3.729101,39.06945 c 0,-0.44788 -0.127964,-3.8709 0.159954,-5.18252 C 4.17558,32.58165 5.114901,27.62704 5.26466,23.74584 5.34362,21.69958 4.88077,14.8204 4.592853,12.90095 4.304935,10.9815 3.857064,5.0632 3.857064,5.0632" />
+    <path d="m 32.594139,39.07641 c 0,-0.44787 0.12797,-3.87089 -0.15995,-5.18252 -0.28653,-1.30528 -1.22585,-6.25989 -1.37561,-10.14108 -0.079,-2.04626 0.38389,-8.92544 0.67181,-10.84489 0.28792,-1.91945 0.73579,-7.83775 0.73579,-7.83775" />
+    <path d="m 5.040724,28.73641 c 0.607826,0 26.040525,-0.12796 26.040525,-0.12796" />
+    <path d="m 3.985027,33.91892 c 0,0 4.766632,-0.47986 7.00599,0.63982 2.239362,1.11968 4.675812,4.13717 6.782052,4.22279 2.66179,0.1082 4.83089,-2.49489 6.84604,-3.90288 1.73958,-1.21546 7.58182,-1.02371 7.58182,-1.02371" />
+  </g>
+</svg>