Add Warm-Up and Stretching activity types

Adds WorkoutActivityType.warmUp (HealthKit .preparationAndRecovery) and
.stretching (.flexibility), and retags the six starter splits that were all
mislabeled as Functional Strength:

- Warm-Up:    Upper Body Warm-Up, Lower Body Warm-Up, Morning Wake-Up
- Stretching: Morning Mobility, Full Body Stretch, Evening Stretch

The split editor's activity picker surfaces them automatically (CaseIterable).
Older app versions decode the new raw values as the default type — additive and
not schema-gated, so no quarantine.

Exercise Library/Seated Row/frames/frame-2.svg

@@ -1,17 +1,37 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 180" fill="none">
   <title>Seated Row</title>
+  <defs>
+    <linearGradient id="grad-leg_l-0" gradientUnits="userSpaceOnUse" x1="145.9" y1="122.8" x2="189.4" y2="108.1"><stop offset="0" stop-color="#a9afba"/><stop offset="1" stop-color="#969ca7"/></linearGradient>
+    <linearGradient id="grad-leg_l-1" gradientUnits="userSpaceOnUse" x1="189.4" y1="108.1" x2="192.0" y2="147.4"><stop offset="0" stop-color="#969ca7"/><stop offset="1" stop-color="#a9afba"/></linearGradient>
+    <linearGradient id="grad-leg_r-1" gradientUnits="userSpaceOnUse" x1="183.9" y1="109.6" x2="188.0" y2="148.8"><stop offset="0" stop-color="#3a3f4b"/><stop offset="1" stop-color="#3d424e"/></linearGradient>
+    <linearGradient id="grad-leg_r-2" gradientUnits="userSpaceOnUse" x1="188.0" y1="148.8" x2="198.9" y2="147.7"><stop offset="0" stop-color="#3d424e"/><stop offset="1" stop-color="#3a3f4b"/></linearGradient>
+  </defs>
   <path d="M 118.3 160.7 L 216.0 160.7 L 216.0 150.3 L 118.3 150.3 Z" fill="none" stroke="#b9bec9" stroke-width="3" stroke-linejoin="round"/>
   <path d="M 122.0 132.0 L 156.0 132.0 L 156.0 132.0 L 122.0 132.0 Z" fill="#c5cad4" stroke="#c5cad4" stroke-width="8" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 159.0 46.0 L 157.0 96.0 L 157.0 96.0 L 159.0 46.0 Z" fill="#c5cad4" stroke="#c5cad4" stroke-width="8" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 176.0 150.0 L 206.0 150.0 L 206.0 150.0 L 176.0 150.0 Z" fill="#c5cad4" stroke="#c5cad4" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 244.0 120.0 L 160.0 73.8" stroke="#c5cad4" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_l" d="M 145.9 122.8 L 189.4 108.1 L 192.0 147.4 L 203.0 146.7" stroke="#a9afba" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_l" d="M 155.5 38.9 L 134.8 60.3 L 162.0 72.8" stroke="#86cfc5" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_l">
+    <path d="M 145.9 122.8 L 189.4 108.1" stroke="url(#grad-leg_l-0)" stroke-width="5.08345" stroke-linecap="round"/>
+    <path d="M 189.4 108.1 L 192.0 147.4" stroke="url(#grad-leg_l-1)" stroke-width="5.08345" stroke-linecap="round"/>
+    <path d="M 192.0 147.4 L 203.0 146.7" stroke="#a9afba" stroke-width="5" stroke-linecap="round"/>
+  </g>
+  <g id="arm_l">
+    <path d="M 155.5 38.9 L 134.8 60.3" stroke="#86cfc5" stroke-width="5" stroke-linecap="round"/>
+    <path d="M 134.8 60.3 L 162.0 72.8" stroke="#86cfc5" stroke-width="5" stroke-linecap="round"/>
+  </g>
   <path id="girdle" d="M 155.5 38.9 L 149.6 38.9 L 149.6 40.8" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="pelvisBar" d="M 145.9 122.8 L 140.0 122.0 L 140.0 123.2" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 140.0 122.0 Q 142.7 79.2 149.6 38.9" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_r" d="M 140.0 123.2 L 183.9 109.6 L 188.0 148.8 L 198.9 147.7" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 149.6 40.8 L 130.3 63.4 L 158.0 74.7" stroke="#0d9488" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_r">
+    <path d="M 140.0 123.2 L 183.9 109.6" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round"/>
+    <path d="M 183.9 109.6 L 188.0 148.8" stroke="url(#grad-leg_r-1)" stroke-width="5.98765" stroke-linecap="round"/>
+    <path d="M 188.0 148.8 L 198.9 147.7" stroke="url(#grad-leg_r-2)" stroke-width="5.98717" stroke-linecap="round"/>
+  </g>
+  <g id="arm_r">
+    <path d="M 149.6 40.8 L 130.3 63.4" stroke="#0d9488" stroke-width="6" stroke-linecap="round"/>
+    <path d="M 130.3 63.4 L 158.0 74.7" stroke="#0d9488" stroke-width="6" stroke-linecap="round"/>
+  </g>
   <path d="M 160.0 80.8 L 160.0 66.8" stroke="#6b7180" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"/>
   <circle id="head" cx="153.1" cy="19.5" r="10" fill="white" stroke="#3a3f4b" stroke-width="6"/>
   <line id="nose" x1="163.0" y1="18.6" x2="170.0" y2="18.0" stroke="#3a3f4b" stroke-width="4" stroke-linecap="round"/>