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/Arm Curl/frames/frame-1.svg

@@ -1,16 +1,36 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 180" fill="none">
   <title>Arm Curl</title>
+  <defs>
+    <linearGradient id="grad-leg_l-0" gradientUnits="userSpaceOnUse" x1="135.9" y1="124.8" x2="179.4" y2="110.0"><stop offset="0" stop-color="#a9afba"/><stop offset="1" stop-color="#969ca7"/></linearGradient>
+    <linearGradient id="grad-leg_l-1" gradientUnits="userSpaceOnUse" x1="179.4" y1="110.0" x2="180.0" y2="149.4"><stop offset="0" stop-color="#969ca7"/><stop offset="1" stop-color="#a9afba"/></linearGradient>
+    <linearGradient id="grad-leg_r-1" gradientUnits="userSpaceOnUse" x1="173.8" y1="111.5" x2="176.0" y2="150.8"><stop offset="0" stop-color="#3a3f4b"/><stop offset="1" stop-color="#3c424d"/></linearGradient>
+    <linearGradient id="grad-leg_r-2" gradientUnits="userSpaceOnUse" x1="176.0" y1="150.8" x2="187.0" y2="150.2"><stop offset="0" stop-color="#3c424d"/><stop offset="1" stop-color="#3b404c"/></linearGradient>
+  </defs>
   <path d="M 115.2 160.7 L 203.0 160.7 L 203.0 150.3 L 115.2 150.3 Z" fill="none" stroke="#b9bec9" stroke-width="3" stroke-linejoin="round"/>
   <path d="M 116.0 134.0 L 150.0 134.0 L 150.0 134.0 L 116.0 134.0 Z" fill="#c5cad4" stroke="#c5cad4" stroke-width="8" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 136.0 52.0 L 164.0 70.0 L 164.0 70.0 L 136.0 52.0 Z" fill="#c5cad4" stroke="#c5cad4" stroke-width="8" stroke-linecap="round" stroke-linejoin="round"/>
   <path d="M 164.0 70.0 L 164.0 128.0" stroke="#c5cad4" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_l" d="M 135.9 124.8 L 179.4 110.0 L 180.0 149.4 L 191.0 149.2" stroke="#a9afba" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_l" d="M 140.3 40.5 L 164.9 57.4 L 186.9 77.6" stroke="#86cfc5" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_l">
+    <path d="M 135.9 124.8 L 179.4 110.0" stroke="url(#grad-leg_l-0)" stroke-width="5.08538" stroke-linecap="round"/>
+    <path d="M 179.4 110.0 L 180.0 149.4" stroke="url(#grad-leg_l-1)" stroke-width="5.08538" stroke-linecap="round"/>
+    <path d="M 180.0 149.4 L 191.0 149.2" stroke="#a9afba" stroke-width="5" stroke-linecap="round"/>
+  </g>
+  <g id="arm_l">
+    <path d="M 140.3 40.5 L 164.9 57.4" stroke="#86cfc5" stroke-width="5" stroke-linecap="round"/>
+    <path d="M 164.9 57.4 L 186.9 77.6" stroke="#86cfc5" stroke-width="5" stroke-linecap="round"/>
+  </g>
   <path id="girdle" d="M 140.3 40.5 L 134.4 40.4 L 134.4 42.3" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="pelvisBar" d="M 135.9 124.8 L 130.0 124.0 L 130.0 125.2" stroke="#3a3f4b" stroke-width="5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 130.0 124.0 Q 130.8 81.1 134.4 40.4" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_r" d="M 130.0 125.2 L 173.8 111.5 L 176.0 150.8 L 187.0 150.2" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 134.4 42.3 L 159.0 59.3 L 180.9 79.4" stroke="#0d9488" stroke-width="6" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_r">
+    <path d="M 130.0 125.2 L 173.8 111.5" stroke="#3a3f4b" stroke-width="6" stroke-linecap="round"/>
+    <path d="M 173.8 111.5 L 176.0 150.8" stroke="url(#grad-leg_r-1)" stroke-width="5.98876" stroke-linecap="round"/>
+    <path d="M 176.0 150.8 L 187.0 150.2" stroke="url(#grad-leg_r-2)" stroke-width="5.98376" stroke-linecap="round"/>
+  </g>
+  <g id="arm_r">
+    <path d="M 134.4 42.3 L 159.0 59.3" stroke="#0d9488" stroke-width="6" stroke-linecap="round"/>
+    <path d="M 159.0 59.3 L 180.9 79.4" stroke="#0d9488" stroke-width="6" stroke-linecap="round"/>
+  </g>
   <path d="M 183.9 84.5 L 183.9 72.5" stroke="#6b7180" stroke-width="4" stroke-linecap="round" stroke-linejoin="round"/>
   <circle id="head" cx="137.2" cy="20.9" r="10" fill="white" stroke="#3a3f4b" stroke-width="6"/>
   <line id="nose" x1="146.7" y1="24.0" x2="153.4" y2="26.1" stroke="#3a3f4b" stroke-width="4" stroke-linecap="round"/>