Add keyboard dismiss toolbar for iOS numeric and multi-line fields

Creates a reusable KeyboardDismissToolbar view modifier that adds a
"Done" button to dismiss keyboards that don't have a return key.
Applied to all numeric keyboards (numberPad, decimalPad, phonePad)
and multi-line text inputs (TextEditor, TextField with axis: .vertical).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

iosApp/iosApp/Task/CompleteTaskView.swift

@@ -112,6 +112,7 @@ struct CompleteTaskView: View {
                                     .foregroundStyle(.secondary)
                             }
                             .padding(.leading, 12)
+                            .keyboardDismissToolbar()
                     } label: {
                         Label(L10n.Tasks.actualCost, systemImage: "dollarsign.circle")
                     }
@@ -132,6 +133,7 @@ struct CompleteTaskView: View {
                         TextEditor(text: $notes)
                             .frame(minHeight: 100)
                             .scrollContentBackground(.hidden)
+                            .keyboardDismissToolbar()
                     }
                 } footer: {
                     Text(L10n.Tasks.optionalNotes)