Redesign onboarding and paywall for 1.2.0

- Onboarding: replace feature-focused slides with outcome-focused copy
  ("Know exactly where you stand", "5 minutes a month is enough", etc.)
- Paywall: non-scrollable layout, reduce from 8 to 4 key benefits,
  remove transactional language (Unlock/Upgrade/Premium),
  new CTA "Get Full Access", floating close button
- Add IAPService.paywallBenefits for the condensed 4-item paywall list
- Update CompactPaywallBanner and PremiumLockOverlay copy

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PortfolioJournal/Views/Onboarding/OnboardingView.swift

@@ -14,28 +14,28 @@ struct OnboardingView: View {
 
     private let pages: [OnboardingPage] = [
         OnboardingPage(
-            icon: "chart.pie.fill",
-            title: "Long-Term Tracking",
-            description: "A calm, offline-first portfolio tracker for investors who update monthly.",
+            icon: "chart.line.uptrend.xyaxis",
+            title: "Know exactly where you stand",
+            description: "See your total wealth, real returns, and allocation — always up to date.",
             color: .appPrimary
         ),
         OnboardingPage(
-            icon: "calendar.circle.fill",
-            title: "Monthly Check-ins",
-            description: "Build a deliberate habit. Update sources, log contributions, and add a short note.",
+            icon: "checkmark.circle.fill",
+            title: "5 minutes a month is enough",
+            description: "Log your values once a month. Portfolio Journal handles the math and shows your progress.",
             color: .positiveGreen
         ),
         OnboardingPage(
-            icon: "bell.badge.fill",
-            title: "Gentle Reminders",
-            description: "Get a monthly nudge to review your portfolio without realtime noise.",
-            color: .appWarning
+            icon: "leaf.fill",
+            title: "Ignore the noise. Track the trend.",
+            description: "Daily swings don't tell the real story. Your growth over months and years does.",
+            color: .appSecondary
         ),
         OnboardingPage(
-            icon: "leaf.fill",
-            title: "Calm Mode",
-            description: "Hide short-term swings and focus on contributions and long-term growth.",
-            color: .appSecondary
+            icon: "flag.checkered",
+            title: "Reach your financial goals",
+            description: "Set targets, track milestones, and see exactly how far you've come.",
+            color: .appWarning
         )
     ]