Add watchOS support

meterios-watch/views/ContentView.swift

@@ -0,0 +1,81 @@
+//
+//  ContentView.swift
+//  meterios-watch
+//
+//  (c) 2025 Martin "maride" Dessauer
+//
+
+import SwiftUI
+
+struct ContentView: View {
+    private var wcMgr: WCManager
+    
+    @State private var drinks: Array<Drink> = []
+    
+    @State private var showUpdateError: Bool = false
+    @State private var updateError: String = ""
+    @State private var updateErrorCount: Int = 0
+    
+    init(_ wcMgr: WCManager) {
+        self.wcMgr = wcMgr
+    }
+    
+    // update performs a full update from the paired device, covering connection info (user ID and backend address) and list of drinks
+    func update() {
+        if updateErrorCount >= 3 {
+            showUpdateError = true
+            updateErrorCount = 0
+            return
+        }
+        
+        // Update drinks list from paired device
+        wcMgr.requestDrinksList(
+            replyHandler: { drinks in
+                // Drinks received from backend
+                self.drinks = drinks
+                showUpdateError = false
+            }, errorHandler: { error in
+                // Error receiving drinks
+                print("Error receiving drinks: \(error)")
+                updateError = error?.localizedDescription ?? "Unknown error"
+                updateErrorCount += 1
+                update()
+            }
+        )
+    }
+    
+    var body: some View {
+        ZStack {
+            if drinks.count > 0 {
+                NavigationView {
+                    List() {
+                        // Drinks
+                        Section("Drinks") {
+                            ForEach(drinks) { drink in
+                                NavigationLink(drink.name) {
+                                    DrinkDetailView(wcMgr: wcMgr, drink: drink)
+                                }
+                            }
+                        }
+                        
+                        // Controls
+                        Section {
+                            Button("Refresh") {
+                                drinks = []
+                                update()
+                            }
+                        }
+                    }
+                }
+            } else {
+                ProgressView()
+            }
+        }
+        .onAppear(perform: update)
+        // Alert to communicate an error in communication with the paired device
+        .alert("Connection Error", isPresented: $showUpdateError) {
+            Text(updateError).tint(.red).font(.footnote)
+            Button("Retry", systemImage: "arrow.clockwise", action: update)
+        }
+    }
+}