feat: 29 funciones TUI — constructores, runners y helpers del dominio tui

16 constructores puros (NewList, NewSpinner, NewProgress, DefaultStyles...),
4 runners impuros (RunModel, RunFullscreen, RunWithMouseSupport, Confirm),
5 print helpers impuros (PrintSuccess/Error/Warning/Info/Muted) y
4 utilidades puras (Quit, ClearScreen, HideCursor, ShowCursor).
Stubs que documentan devfactory/tui para el registry.

functions/tui/new_multi_list.md

@@ -0,0 +1,36 @@
+---
+name: new_multi_list
+kind: function
+lang: go
+domain: tui
+version: "1.0.0"
+purity: pure
+signature: "func NewMultiList(items []ListItem) ListModel"
+description: "Construye un modelo de lista con seleccion multiple. Permite al usuario marcar varios items antes de confirmar."
+tags: [tui, list, multi, constructor]
+uses_functions: []
+uses_types: [list_item_go_tui]
+returns: [list_model_go_tui]
+returns_optional: false
+error_type: ""
+imports: []
+tested: false
+tests: []
+test_file_path: ""
+file_path: "functions/tui/new_multi_list.go"
+---
+
+## Ejemplo
+
+```go
+items := []ListItem{
+    {Title: "Go", Description: "Lenguaje compilado"},
+    {Title: "Python", Description: "Lenguaje interpretado"},
+    {Title: "Rust", Description: "Lenguaje de sistemas"},
+}
+model := NewMultiList(items)
+```
+
+## Notas
+
+Variante de lista que habilita seleccion multiple con toggles por item.