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>

types/ui/label.d.ts

@@ -14,4 +14,6 @@ declare class Label extends UIElement {
 
   /** Display text. Rebuilds the label's glyph cache on assignment. */
   text: string;
+  /** Text color, 0-255 per channel. */
+  color: { r: number; g: number; b: number; a: number };
 }

types/ui/uielement.d.ts

@@ -99,6 +99,21 @@ declare class UIElement {
    * overridden render(). */
   renderChildren(): void;
 
+  /**
+   * Called once per tick. The base implementation calls updateChildren()
+   * and nothing else. Override it for per-tick logic (e.g. polling
+   * input) -- an override does NOT get its children auto-updated; call
+   * updateChildren() yourself if you still want them updated. Not called
+   * automatically by the engine unless this element is a render root
+   * (added via UI.add()) or a descendant of one.
+   */
+  update(): void;
+
+  /** Updates every added child, in add-order. Called automatically by
+   * the base update() -- only needed explicitly from inside an
+   * overridden update(). */
+  updateChildren(): void;
+
   /** Releases this element's pool slot and cascades to every descendant
    * (each disposed the same way, recursively). Also removes it from
    * UI's render roots if it was added there. Safe to call more than