Start dialog: bigger centered title, share icon with more left padding

Replaces confirmationDialog with a custom sheet for better title styling.
Increases share icon trailing padding in TotalValueCard.

Fixes #17

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

PortfolioJournal/Views/Dashboard/DashboardView.swift

@@ -282,18 +282,21 @@ struct TotalValueCard: View {
 
     var body: some View {
         VStack(spacing: 8) {
-            ZStack(alignment: .trailing) {
+            HStack {
+                Spacer()
                 Text("Total Portfolio Value")
-                    .font(.headline.weight(.semibold))
+                    .font(.title3.weight(.bold))
                     .foregroundColor(.white.opacity(0.85))
-
+                Spacer()
+            }
+            .overlay(alignment: .trailing) {
                 if let onShareTap {
                     Button(action: onShareTap) {
                         Image(systemName: "square.and.arrow.up")
                             .font(.subheadline.weight(.semibold))
                             .foregroundColor(.white.opacity(0.9))
                     }
-                    .padding(.trailing, 8)
+                    .padding(.trailing, 16)
                 }
             }
 
@@ -525,20 +528,46 @@ struct MonthlyCheckInCard: View {
         .background(Color(.systemBackground))
         .cornerRadius(AppConstants.UI.cornerRadius)
         .shadow(color: .black.opacity(0.05), radius: 8, y: 2)
-        .confirmationDialog(
-            "Start Monthly Check-in",
-            isPresented: $showingStartOptions,
-            titleVisibility: .visible
-        ) {
-            Button("Start from scratch") {
-                shouldDuplicatePrevious = false
-                startDestinationActive = true
+        .sheet(isPresented: $showingStartOptions) {
+            VStack(spacing: 16) {
+                Text("Start Monthly Check-in")
+                    .font(.title2.weight(.bold))
+                    .multilineTextAlignment(.center)
+                    .padding(.top, 24)
+
+                Button {
+                    showingStartOptions = false
+                    shouldDuplicatePrevious = false
+                    startDestinationActive = true
+                } label: {
+                    Text("Start from scratch")
+                        .font(.headline)
+                        .frame(maxWidth: .infinity)
+                        .padding(.vertical, 14)
+                        .background(Color(.systemGray5))
+                        .cornerRadius(AppConstants.UI.cornerRadius)
+                }
+
+                Button {
+                    showingStartOptions = false
+                    shouldDuplicatePrevious = true
+                    startDestinationActive = true
+                } label: {
+                    Text("Duplicate previous month")
+                        .font(.headline)
+                        .frame(maxWidth: .infinity)
+                        .padding(.vertical, 14)
+                        .background(Color(.systemGray5))
+                        .cornerRadius(AppConstants.UI.cornerRadius)
+                }
+
+                Button("Cancel", role: .cancel) {
+                    showingStartOptions = false
+                }
+                .padding(.bottom, 16)
             }
-            Button("Duplicate previous month") {
-                shouldDuplicatePrevious = true
-                startDestinationActive = true
-            }
-            Button("Cancel", role: .cancel) {}
+            .padding(.horizontal, 24)
+            .presentationDetents([.height(280)])
         }
     }