build iOS study scaffold

mobile/ios-app/Features/Onboarding/OnboardingView.swift

@@ -1,18 +1,34 @@
 import SwiftUI
 
 struct OnboardingView: View {
+    @EnvironmentObject private var localization: LocalizationStore
+
     var body: some View {
-        VStack(alignment: .leading, spacing: 12) {
-            Text("Study intro")
-                .font(.headline)
-            Text("Watch the clip, make your choice before lock, then see the reveal.")
-                .foregroundStyle(.secondary)
-            Button("Start session") {}
-                .buttonStyle(.borderedProminent)
+        VStack(alignment: .leading, spacing: HermesTheme.sectionSpacing) {
+            HermesSectionHeader(
+                title: localization.string(for: "onboarding.title"),
+                subtitle: localization.string(for: "onboarding.subtitle")
+            )
+
+            VStack(alignment: .leading, spacing: 12) {
+                Label {
+                    Text(localization.string(for: "onboarding.consent_body"))
+                } icon: {
+                    Image(systemName: "checkmark.shield.fill")
+                        .foregroundStyle(HermesTheme.accent)
+                }
+
+                Text(localization.string(for: "onboarding.consent_note"))
+                    .font(.callout)
+                    .foregroundStyle(HermesTheme.textSecondary)
+            }
+
+            Button {
+            } label: {
+                Text(localization.string(for: "onboarding.start_session"))
+            }
+                .buttonStyle(HermesPrimaryButtonStyle())
         }
-        .padding()
-        .background(HermesTheme.surface)
-        .foregroundStyle(HermesTheme.textPrimary)
-        .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
+        .hermesCard(elevated: true)
     }
 }