Scene.set() JS lifecycle, UI sprite caching, emulator test scripts

- Add Scene.set(module) so JerryScript can switch scenes via
  require()'d {init, update, dispose} modules; wire it into
  engineUpdate() and rework overworldscene.js/init.js to the new shape.
- Fix scriptManagerExecFile() never pushing its own file's directory
  onto the require() dir stack, breaking relative require() calls from
  a top-level entry script (e.g. init.js -> ./overworldscene.js).
- Cache sprite geometry across frames for uislider/uitab/uiframe
  (dialogs/textbox/settings) and give uitextbox a per-page glyph cache
  instead of one spriteBatchBuffer call per visible character. uiconsole
  drops its alloc/free vertex buffer for a fixed-size one. uifps skips
  rebuilding its label when the text hasn't changed.
- Add PSP_OPTIMIZATION_PLAN.md and a handful of UI/spritebatch unit
  tests covering the new caching logic.
- Add Dolphin/PPSSPP emulator smoke-test scripts (+ Docker variants and
  CI jobs) for GameCube/Wii/PSP.

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

test/ui/test_uiframe.c

@@ -0,0 +1,68 @@
+/**
+ * Copyright (c) 2026 Dominic Masters
+ *
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#include "dusktest.h"
+#include "ui/frame/uiframe.h"
+
+static void test_uiFrameBuildSprites_layout(void **state) {
+  UI_FRAME.tileset = (tileset_t){
+    .tileWidth = 1,
+    .tileHeight = 1,
+    .tileCount = 9,
+    .columns = 3,
+    .rows = 3,
+    .uv = { 0.25f, 0.25f }
+  };
+
+  const float_t x = 100.0f;
+  const float_t y = 50.0f;
+  const float_t width = 40.0f;
+  const float_t height = 30.0f;
+  const float_t tileW = (float_t)UI_FRAME_BORDER_WIDTH;
+  const float_t tileH = (float_t)UI_FRAME_BORDER_HEIGHT;
+
+  spritebatchsprite_t sprites[9];
+  uiFrameBuildSprites(sprites, x, y, width, height);
+
+  // Top-left corner sits exactly at the rect's origin.
+  assert_float_equal(sprites[0].min[0], x, 0.0001f);
+  assert_float_equal(sprites[0].min[1], y, 0.0001f);
+  assert_float_equal(sprites[0].max[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[0].max[1], y + tileH, 0.0001f);
+  assert_float_equal(sprites[0].uvMin[0], 0.0f, 0.0001f);
+  assert_float_equal(sprites[0].uvMin[1], 0.0f, 0.0001f);
+  assert_float_equal(sprites[0].uvMax[0], 0.25f, 0.0001f);
+  assert_float_equal(sprites[0].uvMax[1], 0.25f, 0.0001f);
+
+  // Top-middle edge stretches to fill the width minus both corners.
+  assert_float_equal(sprites[1].min[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[1].max[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[1].max[1], y + tileH, 0.0001f);
+
+  // Center tile fills the remaining interior on both axes.
+  assert_float_equal(sprites[4].min[0], x + tileW, 0.0001f);
+  assert_float_equal(sprites[4].min[1], y + tileH, 0.0001f);
+  assert_float_equal(sprites[4].max[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[4].max[1], y + height - tileH, 0.0001f);
+
+  // Bottom-right corner sits exactly at the rect's far corner, sampling
+  // tileset column 2, row 2.
+  assert_float_equal(sprites[8].min[0], x + width - tileW, 0.0001f);
+  assert_float_equal(sprites[8].min[1], y + height - tileH, 0.0001f);
+  assert_float_equal(sprites[8].max[0], x + width, 0.0001f);
+  assert_float_equal(sprites[8].max[1], y + height, 0.0001f);
+  assert_float_equal(sprites[8].uvMin[0], 0.5f, 0.0001f);
+  assert_float_equal(sprites[8].uvMin[1], 0.5f, 0.0001f);
+}
+
+int main(int argc, char **argv) {
+  const struct CMUnitTest tests[] = {
+    cmocka_unit_test(test_uiFrameBuildSprites_layout),
+  };
+
+  return cmocka_run_group_tests(tests, NULL, NULL);
+}