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/Hip Circles/frames/frame-3.svg

@@ -1,13 +1,33 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 320 180" fill="none">
   <title>Hip Circles</title>
+  <defs>
+    <linearGradient id="grad-leg_l-0" gradientUnits="userSpaceOnUse" x1="166.4" y1="90.1" x2="167.7" y2="121.9"><stop offset="0" stop-color="#3e434f"/><stop offset="1" stop-color="#a9afba"/></linearGradient>
+    <linearGradient id="grad-leg_r-1" gradientUnits="userSpaceOnUse" x1="156.5" y1="122.1" x2="155.9" y2="149.6"><stop offset="0" stop-color="#3a3f4b"/><stop offset="1" stop-color="#989ea9"/></linearGradient>
+    <linearGradient id="grad-leg_r-2" gradientUnits="userSpaceOnUse" x1="155.9" y1="149.6" x2="161.4" y2="150.7"><stop offset="0" stop-color="#989ea9"/><stop offset="1" stop-color="#3a3f4b"/></linearGradient>
+    <linearGradient id="grad-arm_l-1" gradientUnits="userSpaceOnUse" x1="180.0" y1="42.3" x2="186.5" y2="41.7"><stop offset="0" stop-color="#a9afba"/><stop offset="1" stop-color="#9da3ae"/></linearGradient>
+  </defs>
   <path d="M 115.1 151.2 L 180.7 162.6 L 210.4 157.4 L 144.8 146.0 Z" fill="none" stroke="#b9bec9" stroke-width="2.1" stroke-linejoin="round"/>
-  <path id="leg_l" d="M 166.4 90.1 L 167.7 121.9 L 164.2 149.2 L 171.3 150.6" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="leg_r" d="M 156.5 90.3 L 156.5 122.1 L 155.8 149.7 L 162.5 150.5" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_l" d="M 170.6 31.6 L 180.0 42.3 L 186.5 41.7" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="leg_l">
+    <path d="M 166.4 90.1 L 167.7 121.9" stroke="url(#grad-leg_l-0)" stroke-width="3.8363" stroke-linecap="round"/>
+    <path d="M 167.7 121.9 L 165.3 148.9" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+    <path d="M 165.3 148.9 L 170.7 150.8" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+  </g>
+  <g id="leg_r">
+    <path d="M 156.5 90.3 L 156.5 122.1" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round"/>
+    <path d="M 156.5 122.1 L 155.9 149.6" stroke="url(#grad-leg_r-1)" stroke-width="3.90409" stroke-linecap="round"/>
+    <path d="M 155.9 149.6 L 161.4 150.7" stroke="url(#grad-leg_r-2)" stroke-width="3.90409" stroke-linecap="round"/>
+  </g>
+  <g id="arm_l">
+    <path d="M 170.6 31.6 L 180.0 42.3" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+    <path d="M 180.0 42.3 L 186.5 41.7" stroke="url(#grad-arm_l-1)" stroke-width="3.53721" stroke-linecap="round"/>
+  </g>
   <path id="girdle" d="M 170.6 31.6 L 162.2 31.6 L 156.7 32.5" stroke="#0d9488" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="pelvisBar" d="M 166.4 90.1 L 160.0 89.7 L 156.5 90.3" stroke="#0d9488" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 160.0 89.7 Q 160.4 59.8 162.2 31.6" stroke="#0d9488" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 156.7 32.5 L 143.4 47.2 L 162.9 44.3" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
+  <g id="arm_r">
+    <path d="M 156.7 32.5 L 143.4 47.2" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round"/>
+    <path d="M 143.4 47.2 L 162.9 44.3" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round"/>
+  </g>
   <circle id="head" cx="162.9" cy="17.9" r="7.0" fill="white" stroke="#3a3f4b" stroke-width="4.2"/>
   <line id="nose" x1="169.6" y1="19.8" x2="173.1" y2="20.7" stroke="#3a3f4b" stroke-width="2.8" stroke-linecap="round"/>
   <g font-family="-apple-system, Helvetica, sans-serif" font-size="11" fill="#6b7180">