feat(home): custom SVG zone icons for body-zone cards

Replace the hand-drawn Path silhouettes in ZoneHighlightIcon with
polished vector SVG artwork (upper/lower/full body figures).

- Add ZoneIconUpper/Lower/Full.imagesets to Assets.xcassets with
  preserves-vector-representation for crisp rendering at any size
- Rewrite ZoneHighlightIcon to load the SVG assets via Image with
  scaledToFit, preserving the zone: String API so ZoneCard is unchanged

Verified: xcodegen + xcodebuild (Swift 6 strict concurrency) succeeds;
rendered on iPhone 17 Pro simulator.

tabatago-swift/TabataGo/Views/Components/ZoneHighlightIcon.swift

@@ -1,131 +1,35 @@
 import SwiftUI
 
-struct BodySilhouetteShape: Shape {
-    func path(in rect: CGRect) -> Path {
-        let w = rect.width
-        let h = rect.height
-        let mx = w * 0.5
-        var p = Path()
-
-        let headCY = h * 0.09
-        let headR = w * 0.12
-        p.addEllipse(in: CGRect(
-            x: mx - headR, y: headCY - headR,
-            width: headR * 2, height: headR * 2
-        ))
-
-        let neckW = w * 0.06
-        let neckTop = headCY + headR
-        let shoulderY = h * 0.20
-        p.addRect(CGRect(
-            x: mx - neckW, y: neckTop,
-            width: neckW * 2, height: shoulderY - neckTop
-        ))
-
-        let shoulderHW = w * 0.42
-        let armOuterBotY = h * 0.44
-        let armInnerBotY = h * 0.44
-        let armOuterX = w * 0.06
-        let armInnerX = w * 0.12
-
-        p.move(to: CGPoint(x: mx - neckW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx - shoulderHW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx - armOuterX, y: armOuterBotY))
-        p.addLine(to: CGPoint(x: mx - armInnerX, y: armInnerBotY))
-        p.closeSubpath()
-
-        p.move(to: CGPoint(x: mx + neckW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx + shoulderHW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx + armOuterX, y: armOuterBotY))
-        p.addLine(to: CGPoint(x: mx + armInnerX, y: armInnerBotY))
-        p.closeSubpath()
-
-        let torsoHW = w * 0.18
-        let waistY = h * 0.46
-        let waistHW = w * 0.15
-        p.move(to: CGPoint(x: mx - torsoHW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx + torsoHW, y: shoulderY))
-        p.addLine(to: CGPoint(x: mx + waistHW, y: waistY))
-        p.addLine(to: CGPoint(x: mx - waistHW, y: waistY))
-        p.closeSubpath()
-
-        let hipHW = w * 0.22
-        let hipY = h * 0.52
-        p.move(to: CGPoint(x: mx - waistHW, y: waistY))
-        p.addLine(to: CGPoint(x: mx + waistHW, y: waistY))
-        p.addLine(to: CGPoint(x: mx + hipHW, y: hipY))
-        p.addLine(to: CGPoint(x: mx - hipHW, y: hipY))
-        p.closeSubpath()
-
-        let gap = w * 0.02
-        let legBotY = h * 0.92
-        let footH = h * 0.05
-        let footExtra = w * 0.04
-
-        p.move(to: CGPoint(x: mx - hipHW, y: hipY))
-        p.addLine(to: CGPoint(x: mx - gap, y: hipY))
-        p.addLine(to: CGPoint(x: mx - gap, y: legBotY))
-        p.addLine(to: CGPoint(x: mx - hipHW - footExtra, y: legBotY + footH))
-        p.addLine(to: CGPoint(x: mx - hipHW, y: legBotY))
-        p.closeSubpath()
-
-        p.move(to: CGPoint(x: mx + gap, y: hipY))
-        p.addLine(to: CGPoint(x: mx + hipHW, y: hipY))
-        p.addLine(to: CGPoint(x: mx + hipHW, y: legBotY))
-        p.addLine(to: CGPoint(x: mx + hipHW + footExtra, y: legBotY + footH))
-        p.addLine(to: CGPoint(x: mx + gap, y: legBotY))
-        p.closeSubpath()
-
-        return p
-    }
-}
-
+/// Body-zone highlight icon backed by vector SVG assets in `Assets.xcassets`.
+///
+/// Each zone renders its own artwork:
+/// - `upper-body` → `ZoneIconUpper`
+/// - `lower-body` → `ZoneIconLower`
+/// - `full-body`  → `ZoneIconFull`
+///
+/// The SVGs ship with their own baked-in colors, so the icon is **not**
+/// tinted by `Theme.zoneGradient` — it shows the artwork as authored.
+/// To make icons auto-recolor per zone instead, switch the imagesets to
+/// single-color SVGs and set `"template-rendering-intent": "template"`
+/// in each `Contents.json`, then apply `.foregroundStyle(...)` here.
+///
+/// Drawn on a 56×80 frame with `scaledToFit()` so the SVG keeps its
+/// native aspect ratio inside the card.
 struct ZoneHighlightIcon: View {
     let zone: String
 
-    private var waistFraction: CGFloat { 0.50 }
-
     var body: some View {
-        let shape = BodySilhouetteShape()
-        ZStack {
-            shape
-                .fill(.white.opacity(0.12))
-
-            shape
-                .fill(zoneGradient)
-                .mask(zoneMask)
-        }
-        .frame(width: 56, height: 80)
+        Image(decorative: imageName, bundle: .main)
+            .resizable()
+            .scaledToFit()
+            .frame(width: 56, height: 80)
     }
 
-    private var zoneGradient: LinearGradient {
-        switch zone {
-        case "upper-body":
-            LinearGradient(colors: [.orange, .red.opacity(0.8)], startPoint: .top, endPoint: .bottom)
-        case "lower-body":
-            LinearGradient(colors: [.blue, .purple.opacity(0.8)], startPoint: .top, endPoint: .bottom)
-        case "full-body":
-            LinearGradient(colors: [Theme.brand, .purple], startPoint: .top, endPoint: .bottom)
-        default:
-            LinearGradient(colors: [.gray, .secondary], startPoint: .top, endPoint: .bottom)
-        }
-    }
-
-    @ViewBuilder
-    private var zoneMask: some View {
-        switch zone {
-        case "upper-body":
-            Rectangle()
-                .frame(height: 80 * waistFraction)
-                .frame(maxHeight: .infinity, alignment: .top)
-        case "lower-body":
-            Rectangle()
-                .frame(height: 80 * waistFraction)
-                .frame(maxHeight: .infinity, alignment: .bottom)
-        case "full-body":
-            Rectangle()
-        default:
-            Rectangle()
+    private var imageName: String {
+        switch zone.lowercased() {
+        case "upper-body", "upper": return "ZoneIconUpper"
+        case "lower-body", "lower": return "ZoneIconLower"
+        default:                    return "ZoneIconFull"
         }
     }
 }