Restrict contribution fields to detailed mode only

AddSnapshotView: restore inputMode == .detailed guard for contribution section.
BatchUpdateView: show contribution field per row only when the source's
account is configured with inputMode == .detailed.

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

PortfolioJournal/Views/Sources/AddSourceView.swift

@@ -499,22 +499,24 @@ struct AddSnapshotView: View {
                     }
                 }
 
-                Section {
-                    Toggle("Include Contribution", isOn: $viewModel.includeContribution)
+                if viewModel.inputMode == .detailed {
+                    Section {
+                        Toggle("Include Contribution", isOn: $viewModel.includeContribution)
 
-                    if viewModel.includeContribution {
-                        HStack {
-                            Text(viewModel.currencySymbol)
-                                .foregroundColor(.secondary)
+                        if viewModel.includeContribution {
+                            HStack {
+                                Text(viewModel.currencySymbol)
+                                    .foregroundColor(.secondary)
 
-                            TextField("New capital added", text: $viewModel.contributionString)
-                                .keyboardType(.decimalPad)
+                                TextField("New capital added", text: $viewModel.contributionString)
+                                    .keyboardType(.decimalPad)
+                            }
                         }
+                    } header: {
+                        Text("Contribution (Optional)")
+                    } footer: {
+                        Text("Track new capital added to separate it from investment growth.")
                     }
-                } header: {
-                    Text("Contribution (Optional)")
-                } footer: {
-                    Text("Track new capital added to separate it from investment growth.")
                 }
 
                 Section {