feat: use ConfettiSwiftUI package instead of custom confetti

- import ConfettiSwiftUI
- .confettiCannon modifier on MainTabView
- 80 particles, circles/crosses/rectangles, 7 colors
- Trigger: confettiTrigger += 1
- Removed all custom confetti code (ConfettiView, PhysicsModifier, etc.)

Requires: Add package in Xcode → https://github.com/simibac/ConfettiSwiftUI

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ios/Platform/.stignore

@@ -0,0 +1,13 @@
+// Xcode user data — changes every build, ignore
+Platform.xcodeproj/xcuserdata
+Platform.xcodeproj/project.xcworkspace/xcuserdata
+Platform.xcodeproj/project.xcworkspace/xcshareddata
+
+// Build artifacts
+DerivedData
+build
+.build
+
+// macOS files
+.DS_Store
+*.xcuserstate

ios/Platform/Platform/ContentView.swift

@@ -1,4 +1,5 @@
 import SwiftUI
+import ConfettiSwiftUI
 
 struct ContentView: View {
     @Environment(AuthManager.self) private var auth
@@ -24,7 +25,7 @@ struct ContentView: View {
 struct MainTabView: View {
     @State private var selectedTab = 0
     @State private var showAssistant = false
-    @State private var showConfetti = false
+    @State private var confettiTrigger = 0
 
     var body: some View {
         ZStack {
@@ -57,14 +58,18 @@ struct MainTabView: View {
                 }
                 .padding(.bottom, 70)
             }
-
-            // Confetti overlay
-            if showConfetti {
-                ConfettiView()
-                    .ignoresSafeArea()
-                    .allowsHitTesting(false)
-            }
         }
+        .confettiCannon(
+            counter: $confettiTrigger,
+            num: 80,
+            confettis: [.shape(.circle), .shape(.roundedCross), .shape(.slimRectangle)],
+            colors: [.red, .orange, .yellow, .green, .blue, .purple, .pink],
+            confettiSize: 8,
+            rainHeight: 600,
+            openingAngle: Angle.degrees(40),
+            closingAngle: Angle.degrees(140),
+            radius: 300
+        )
         .sheet(isPresented: $showAssistant) {
             AssistantSheetView(onFoodAdded: foodAdded)
         }
@@ -73,117 +78,8 @@ struct MainTabView: View {
     private func foodAdded() {
         showAssistant = false
         selectedTab = 1
-        triggerConfetti()
-    }
-
-    private func triggerConfetti() {
-        showConfetti = true
+        confettiTrigger += 1
         UINotificationFeedbackGenerator().notificationOccurred(.success)
-        DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
-            showConfetti = false
-        }
-    }
-}
-
-// MARK: - Confetti (ReactFlux style: ceiling drop, full screen scatter)
-
-struct ConfettiView: View {
-    @State private var particles: [ConfettiPiece] = []
-
-    static let colors: [Color] = [
-        Color(red: 1, green: 0.22, blue: 0.36),    // hot pink
-        Color(red: 0.26, green: 0.63, blue: 1),     // sky blue
-        Color(red: 1, green: 0.84, blue: 0),         // gold
-        Color(red: 0.18, green: 0.8, blue: 0.44),    // green
-        Color(red: 0.61, green: 0.35, blue: 0.96),   // purple
-        Color(red: 1, green: 0.55, blue: 0),          // orange
-        Color(red: 0, green: 0.82, blue: 0.77),       // teal
-        Color(red: 1, green: 0.41, blue: 0.71),       // pink
-        Color(red: 0.39, green: 0.4, blue: 1),        // indigo
-        Color(red: 1, green: 0.92, blue: 0.23),       // yellow
-    ]
-
-    struct ConfettiPiece: Identifiable {
-        let id = UUID()
-        let color: Color
-        let width: CGFloat
-        let height: CGFloat
-        let x: CGFloat
-        let startY: CGFloat
-        let drift: CGFloat
-        let spin: Double
-        let delay: Double
-        let fallDuration: Double
-    }
-
-    var body: some View {
-        GeometryReader { geo in
-            ZStack {
-                ForEach(particles) { p in
-                    RoundedRectangle(cornerRadius: 1)
-                        .fill(p.color)
-                        .frame(width: p.width, height: p.height)
-                        .modifier(CeilingDropModifier(
-                            x: p.x, startY: p.startY,
-                            endY: geo.size.height + 40,
-                            drift: p.drift, spin: p.spin,
-                            delay: p.delay, duration: p.fallDuration
-                        ))
-                }
-            }
-            .onAppear { scatter(in: geo.size) }
-        }
-    }
-
-    private func scatter(in size: CGSize) {
-        particles = (0..<200).map { _ in
-            ConfettiPiece(
-                color: Self.colors.randomElement()!,
-                width: CGFloat.random(in: 4...8),
-                height: CGFloat.random(in: 6...14),
-                x: CGFloat.random(in: 0...size.width),
-                startY: CGFloat.random(in: (-200)...(-20)),
-                drift: CGFloat.random(in: -30...30),
-                spin: Double.random(in: -540...540),
-                delay: Double.random(in: 0...0.4),
-                fallDuration: Double.random(in: 1.5...2.5)
-            )
-        }
-        UINotificationFeedbackGenerator().notificationOccurred(.success)
-    }
-}
-
-struct CeilingDropModifier: ViewModifier {
-    let x: CGFloat
-    let startY: CGFloat
-    let endY: CGFloat
-    let drift: CGFloat
-    let spin: Double
-    let delay: Double
-    let duration: Double
-
-    @State private var progress: CGFloat = 0
-    @State private var opacity: Double = 1
-
-    func body(content: Content) -> some View {
-        content
-            .position(
-                x: x + drift * progress,
-                y: startY + (endY - startY) * progress
-            )
-            .opacity(opacity)
-            .rotation3DEffect(
-                Angle.degrees(spin * Double(progress)),
-                axis: (x: Double.random(in: 0...1), y: Double.random(in: 0...1), z: 0.5)
-            )
-            .onAppear {
-                withAnimation(.easeIn(duration: duration).delay(delay)) {
-                    progress = 1
-                }
-                withAnimation(.easeIn(duration: 0.3).delay(delay + duration * 0.8)) {
-                    opacity = 0
-                }
-            }
     }
 }