Add internal/kubeexec wrapper and cmd/kctl-tui entrypoint (main, full mode)

cmd/kctl-tui/list_item.go

@@ -0,0 +1,12 @@
+package main
+
+// simpleItem is a minimal implementation of list.Item used for all
+// selection screens (contexts, teams, namespaces, menu actions).
+type simpleItem struct {
+	label string // what is shown to the user
+	value string // the underlying value (context name, team value, ...)
+}
+
+func (i simpleItem) Title() string       { return i.label }
+func (i simpleItem) Description() string { return "" }
+func (i simpleItem) FilterValue() string { return i.label }