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/Romanian Deadlift/visual.svg

@@ -1,16 +1,37 @@
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   <title>Romanian Deadlift</title>
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+  <defs>
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+    <linearGradient id="grad-arm_l-0" gradientUnits="userSpaceOnUse" x1="169.0" y1="85.3" x2="168.8" y2="106.0"><stop offset="0" stop-color="#a2a7b3"/><stop offset="1" stop-color="#a9afba"/></linearGradient>
+    <linearGradient id="grad-leg_r-1" gradientUnits="userSpaceOnUse" x1="135.7" y1="131.1" x2="156.7" y2="149.4"><stop offset="0" stop-color="#0d9488"/><stop offset="1" stop-color="#1e9c91"/></linearGradient>
+    <linearGradient id="grad-leg_r-2" gradientUnits="userSpaceOnUse" x1="156.7" y1="149.4" x2="160.5" y2="142.8"><stop offset="0" stop-color="#1e9c91"/><stop offset="1" stop-color="#0d9488"/></linearGradient>
+    <linearGradient id="grad-arm_r-1" gradientUnits="userSpaceOnUse" x1="165.3" y1="107.3" x2="166.4" y2="128.0"><stop offset="0" stop-color="#3a3f4b"/><stop offset="1" stop-color="#414652"/></linearGradient>
+  </defs>
+  <path d="M 102.6 157.8 L 197.9 157.8 L 197.9 150.5 L 102.6 150.5 Z" fill="none" stroke="#b9bec9" stroke-width="2.1" stroke-linejoin="round"/>
+  <g id="leg_l">
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+    <path d="M 139.6 131.2 L 160.3 149.7" stroke="#86cfc5" stroke-width="3.5" stroke-linecap="round"/>
+    <path d="M 160.3 149.7 L 164.2 143.2" stroke="#86cfc5" stroke-width="3.5" stroke-linecap="round"/>
+  </g>
+  <g id="arm_l">
+    <path d="M 169.0 85.3 L 168.8 106.0" stroke="url(#grad-arm_l-0)" stroke-width="3.52354" stroke-linecap="round"/>
+    <path d="M 168.8 106.0 L 169.3 126.7" stroke="#a9afba" stroke-width="3.5" stroke-linecap="round"/>
+  </g>
+  <g id="leg_r">
+    <path d="M 111.0 110.9 L 135.7 131.1" stroke="#0d9488" stroke-width="4.2" stroke-linecap="round"/>
+    <path d="M 135.7 131.1 L 156.7 149.4" stroke="url(#grad-leg_r-1)" stroke-width="4.14992" stroke-linecap="round"/>
+    <path d="M 156.7 149.4 L 160.5 142.8" stroke="url(#grad-leg_r-2)" stroke-width="4.14992" stroke-linecap="round"/>
+  </g>
   <path id="girdle" d="M 169.0 85.3 L 164.9 85.3 L 164.9 86.6" stroke="#0d9488" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="pelvisBar" d="M 115.1 110.5 L 111.0 110.0 L 111.0 110.9" stroke="#0d9488" stroke-width="3.5" stroke-linecap="round" stroke-linejoin="round"/>
   <path id="spine" d="M 111.0 110.0 Q 139.9 100.1 164.9 85.3" stroke="#0d9488" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
-  <path id="arm_r" d="M 164.9 86.6 L 165.3 107.3 L 164.9 128.0" stroke="#3a3f4b" stroke-width="4.2" stroke-linecap="round" stroke-linejoin="round"/>
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-  <circle cx="166.4" cy="124.2" r="9.1" fill="#6b7180"/>
-  <circle cx="166.4" cy="130.5" r="9.1" fill="#6b7180"/>
+  <g id="arm_r">
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+    <path d="M 165.3 107.3 L 166.4 128.0" stroke="url(#grad-arm_r-1)" stroke-width="4.17658" stroke-linecap="round"/>
+  </g>
+  <path d="M 167.8 124.2 L 167.8 130.5" stroke="#6b7180" stroke-width="2.8" stroke-linecap="round" stroke-linejoin="round"/>
+  <circle cx="167.8" cy="124.2" r="9.1" fill="#6b7180"/>
+  <circle cx="167.8" cy="130.5" r="9.1" fill="#6b7180"/>
   <circle id="head" cx="177.8" cy="79.9" r="7.0" fill="white" stroke="#3a3f4b" stroke-width="4.2"/>
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