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/Dumbbell Curl/frames/frame-1.svg

@@ -1,13 +1,34 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 180" fill="none">
   <title>Dumbbell Curl</title>
+  <defs>
+    <linearGradient id="grad-leg_l-0" gradientUnits="userSpaceOnUse" x1="164.1" y1="90.9" x2="168.9" y2="122.3"><stop offset="0" stop-color="#505561"/><stop offset="1" stop-color="#a9afba"/></linearGradient>
+    <linearGradient id="grad-leg_r-1" gradientUnits="userSpaceOnUse" x1="165.6" y1="122.5" x2="158.6" y2="149.2"><stop offset="0" stop-color="#3a3f4b"/><stop offset="1" stop-color="#5b606c"/></linearGradient>
+    <linearGradient id="grad-leg_r-2" gradientUnits="userSpaceOnUse" x1="158.6" y1="149.2" x2="166.1" y2="151.1"><stop offset="0" stop-color="#5b606c"/><stop offset="1" stop-color="#616772"/></linearGradient>
+    <linearGradient id="grad-arm_l-0" gradientUnits="userSpaceOnUse" x1="167.3" y1="31.9" x2="167.3" y2="52.6"><stop offset="0" stop-color="#7ecbc1"/><stop offset="1" stop-color="#86cfc5"/></linearGradient>
+    <linearGradient id="grad-arm_r-1" gradientUnits="userSpaceOnUse" x1="163.1" y1="53.9" x2="166.8" y2="74.3"><stop offset="0" stop-color="#0d9488"/><stop offset="1" stop-color="#15988c"/></linearGradient>
+  </defs>
   <path d="M 148.9 157.5 L 192.6 157.5 L 192.6 150.2 L 148.9 150.2 Z" fill="none" stroke="#b9bec9" stroke-width="2.1" stroke-linejoin="round"/>
-  <path id="leg_l" d="M 164.1 90.9 L 168.9 122.3 L 161.4 148.9 L 168.8 150.9" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_r" d="M 160.0 91.3 L 165.6 122.5 L 158.6 149.2 L 166.1 151.1" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_l" d="M 167.3 31.9 L 167.3 52.6 L 170.9 73.0" stroke="#86cfc5" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_l">
+    <path d="M 164.1 90.9 L 168.9 122.3" stroke="url(#grad-leg_l-0)" stroke-width="3.78058" stroke-linecap="round"/>
+    <path d="M 168.9 122.3 L 161.4 148.9" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+    <path d="M 161.4 148.9 L 168.8 150.9" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+  </g>
+  <g id="leg_r">
+    <path d="M 160.0 91.3 L 165.6 122.5" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round"/>
+    <path d="M 165.6 122.5 L 158.6 149.2" stroke="url(#grad-leg_r-1)" stroke-width="4.09677" stroke-linecap="round"/>
+    <path d="M 158.6 149.2 L 166.1 151.1" stroke="url(#grad-leg_r-2)" stroke-width="3.9732" stroke-linecap="round"/>
+  </g>
+  <g id="arm_l">
+    <path d="M 167.3 31.9 L 167.3 52.6" stroke="url(#grad-arm_l-0)" stroke-width="3.52288" stroke-linecap="round"/>
+    <path d="M 167.3 52.6 L 170.9 73.0" stroke="#86cfc5" stroke-width="3.5" stroke-linecap="round"/>
+  </g>
   <path id="girdle" d="M 167.3 31.9 L 163.1 31.9 L 163.1 33.2" stroke="#3a3f4b" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="pelvisBar" d="M 164.1 90.9 L 160.0 90.4 L 160.0 91.3" stroke="#3a3f4b" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 160.0 90.4 Q 161.6 60.5 163.1 31.9" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 163.1 33.2 L 163.1 53.9 L 166.8 74.3" stroke="#0d9488" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="arm_r">
+    <path d="M 163.1 33.2 L 163.1 53.9" stroke="#0d9488" stroke-width="4.2" stroke-linecap="round"/>
+    <path d="M 163.1 53.9 L 166.8 74.3" stroke="url(#grad-arm_r-1)" stroke-width="4.17783" stroke-linecap="round"/>
+  </g>
   <path d="M 171.6 73.4 L 161.9 75.1" stroke="#6b7180" stroke-width="2.0999999999999996" stroke-linecap="round" stroke-linejoin="round"/>
   <circle cx="171.6" cy="73.4" r="3.15" fill="#6b7180"/>
   <circle cx="161.9" cy="75.1" r="3.15" fill="#6b7180"/>