Reimplement the archived UI widget stack on the new element-tree system

The old widget system (archive/dusk/ui/) depended on infrastructure this
rewrite deleted -- a static X-macro element list, a 9-slice UI_FRAME, and
a global gamepad/keyboard focus stack -- so everything below is rebuilt
on top of the new native uielement_t pool + parent/child tree instead,
gamepad/keyboard-only (no mouse support exists in the input system).

New JS widgets (assets/scripts/), all pure composites of Label/Rectangle
following the Button.js pattern: Checkbox, Tab, Slider, Dropdown. Slider/
Dropdown expose a directionInput(dx, dy) hook so a menu can hand them
LEFT/RIGHT before falling back to cursor movement.

New Menu.js replaces the old global uifocus_t stack: a small push/pop
stack of Menu instances where only the topmost consumes CANCEL/ACCEPT/
direction input each tick (needed for nested modals -- a Settings
sub-page menu plus a "discard changes?" Confirm can be open at once).
Held-direction repeat timing matches the old 0.5s delay / 0.1s repeat.

New overlay composites (added via a new UI.addOverlay()/UI.removeOverlay(),
always drawn/updated after normal roots): FpsCounter, ConsoleOverlay
(one Label per console history line, driven directly rather than via
add() since History (16) exceeds the 8-children-per-element cap), Crop
(letterbox/pillarbox bars), and Fullbox (a reusable tweened full-screen
fade covering both the old fullbox and transition effects -- reuses
shared instances rather than allocate-and-dispose, since disposing an
element from inside its own render() callback risks the same JerryScript
refcount corruption hit earlier in this rewrite).

New Confirm.js (Yes/No dialog) and Settings.js (+ SettingsGeneral/
SettingsInput sub-pages) built on Menu. Display/Audio settings pages are
intentionally not ported -- neither had a real backing engine system
even in the old code. Frame is a flat Rectangle for now, not real 9-slice
(a genuinely bigger native lift, deliberately deferred).

Small native binding additions needed by the above, each with its own
unit test: Time.renderDelta, Console.lineCount/getLine/visible/
consumeDirty, a new Screen module, a new Locale module, Input.deadzone,
a new Save module, and Label.color (was missing entirely). Also fixes
a real gap from the UI.addOverlay() work: uiElementDispose() wasn't
removing disposed elements from the new overlay root array, which would
have left dangling ids behind.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

assets/scripts/OverworldScene.js

@@ -1,6 +1,9 @@
 var Player = require('./Player.js');
 var PlayerCamera = require('./PlayerCamera.js');
 var TestPlane = require('./TestPlane.js');
+var TestUIElement = require('./TestUIElement.js');
+var FpsCounter = require('./FpsCounter.js');
+var ConsoleOverlay = require('./ConsoleOverlay.js');
 
 class OverworldScene {
   constructor() {
@@ -11,15 +14,14 @@ class OverworldScene {
     this.plane = new TestPlane();
     this.camera = new PlayerCamera(this.player);
 
-    this.rect = new Rectangle();
-    this.rect.color = { r: 255, g: 0, b: 0, a: 255 };
-    this.rect.width = 100;
-    this.rect.height = 100;
-    UI.add(this.rect);
-    
-    this.label = new Label();
-    this.label.text = 'Hello World!';
-    this.rect.add(this.label);
+    this.testUi = new TestUIElement();
+    UI.add(this.testUi);
+
+    this.fpsCounter = new FpsCounter();
+    UI.addOverlay(this.fpsCounter);
+
+    this.consoleOverlay = new ConsoleOverlay();
+    UI.addOverlay(this.consoleOverlay);
   }
 
   lateUpdate() {
@@ -31,16 +33,19 @@ class OverworldScene {
     this.player.dispose();
     this.plane.dispose();
 
-    // rect.dispose() cascades to label (added as its child) and removes
-    // itself from UI's render roots -- no separate UI.remove()/dispose()
-    // needed for either.
-    this.rect.dispose();
+    // testUi.dispose() cascades to its background/label children and
+    // removes itself from UI's render roots -- no separate UI.remove()
+    // needed.
+    this.testUi.dispose();
+    this.fpsCounter.dispose();
+    this.consoleOverlay.dispose();
 
-    this.camera = null;
+    this.camera = null; 
     this.player = null;
     this.plane = null;
-    this.label = null;
-    this.rect = null;
+    this.testUi = null;
+    this.fpsCounter = null;
+    this.consoleOverlay = null;
   }
 }