feat: add optional server groups

Sources/Views/GroupFormView.swift

@@ -0,0 +1,80 @@
+import SwiftUI
+
+struct GroupFormView: View {
+    enum Mode {
+        case add
+        case edit(ServerGroup)
+    }
+
+    let mode: Mode
+    @Binding var groups: [ServerGroup]
+    let onSave: () -> Void
+
+    @Environment(\.dismiss) private var dismiss
+    @State private var name: String
+
+    init(mode: Mode, groups: Binding<[ServerGroup]>, onSave: @escaping () -> Void) {
+        self.mode = mode
+        self._groups = groups
+        self.onSave = onSave
+
+        switch mode {
+        case .add:
+            self._name = State(initialValue: "")
+        case .edit(let group):
+            self._name = State(initialValue: group.name)
+        }
+    }
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 16) {
+            Text(title)
+                .font(.headline)
+
+            TextField("Group name", text: $name)
+                .textFieldStyle(.roundedBorder)
+
+            HStack {
+                Button("Cancel") {
+                    dismiss()
+                }
+
+                Spacer()
+
+                Button("Save") {
+                    save()
+                }
+                .disabled(trimmedName.isEmpty)
+            }
+        }
+        .padding()
+        .frame(width: 320)
+    }
+
+    private var title: String {
+        switch mode {
+        case .add:
+            return "Add Group"
+        case .edit:
+            return "Edit Group"
+        }
+    }
+
+    private var trimmedName: String {
+        name.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    private func save() {
+        switch mode {
+        case .add:
+            groups.append(ServerGroup(name: trimmedName))
+        case .edit(let group):
+            if let index = groups.firstIndex(where: { $0.id == group.id }) {
+                groups[index].name = trimmedName
+            }
+        }
+
+        onSave()
+        dismiss()
+    }
+}