1.1.5: conversion funnel overhaul

Paywall:
- Redesigned PremiumView with yearly/monthly/lifetime side by side
- 7-day free trial badge with savings % vs monthly
- Social proof line, BEST VALUE highlight on yearly
- StoreManager: new yearlyProduct, lifetimeProduct, yearlySavingsPercent, hasTrialAvailable

Funnel:
- Paywall step added to onboarding (PaywallStepView)
- Contextual modal at dish limit (replaces silent block)
- Visible "X/15 dishes" counter in DishListView
- BottomPromoBanner rotates AdMob with internal "Remove ads" CTA (1 in 4)
- Free dish limit lowered 20 → 15
- Review prompt earlier: 2 weeks → 1 week

Analytics:
- paywall_viewed/dismissed with source + seconds_on_screen
- dish_limit_hit, week_limit_hit, free_trial_started events
- Every PremiumView call site now passes its source

StoreKit:
- MealMood.storekit: added yearly $19.99 + 7d trial, monthly trial, lifetime $39.99
- AppStoreConnect-1.1.5-setup.md with full manual setup instructions

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

MealMood/Views/Settings/SettingsView.swift

@@ -181,7 +181,7 @@ struct SettingsView: View {
                         .foregroundColor(.mealMoodTextSecondary)
                 }
 
-                NavigationLink(destination: PremiumView(settings: settings)) {
+                NavigationLink(destination: PremiumView(settings: settings, source: "settings")) {
                     Text("settings_remove_ads")
                 }
             } header: {