1.1.5: fix activation analytics blind spots + purchase environment tagging

- dish_added now carries a `source` param; onboarding-created dishes fire
  it with source="onboarding" (previously untracked, undercounting activation)
- onboarding_completed now reports dish_count
- premium_purchased tagged with StoreKit environment (production/sandbox/xcode)
  so test purchases can be excluded from conversion metrics
- add .gitignore to keep signing secrets (.p12/.cer/.mobileprovision) and
  build artifacts out of the repo
- document branch↔MARKETING_VERSION naming convention

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UtWT52pAE91D7mbDda1cAM

MealMood/Services/StoreManager.swift

@@ -81,7 +81,7 @@ final class StoreManager: ObservableObject {
                 if case .verified(let transaction) = verification {
                     await transaction.finish()
                     isPremium = true
-                    AnalyticsService.logPremiumPurchased()
+                    AnalyticsService.logPremiumPurchased(environment: Self.environmentName(for: transaction))
                     return .success
                 }
                 return .failed
@@ -181,6 +181,17 @@ final class StoreManager: ObservableObject {
         return false
     }
 
+    /// Maps a transaction's StoreKit environment to an analytics-friendly string
+    /// so sandbox/Xcode test purchases can be excluded from real conversion metrics.
+    static func environmentName(for transaction: StoreKit.Transaction) -> String {
+        switch transaction.environment {
+        case .production: return "production"
+        case .sandbox: return "sandbox"
+        case .xcode: return "xcode"
+        default: return "unknown"
+        }
+    }
+
     private struct TimeoutError: Error {}
 
     private func loadProductsWithRetries(maxAttempts: Int = 3) async throws -> [Product] {