Enabled switch, text assets, mouse input and the jump-and-run example game

Engine additions that the example game needed:
- `enabled` as a shared property of every placeable asset (default on, an
  override on the scene object). A switched-off object is not drawn, does not
  collide and its behavior does not run - and neither does anything parented
  below it. Disabled objects are now hidden in the scene view as well, so the
  editor shows what the game shows; they stay in the hierarchy panel, which is
  where they are selected and switched back on.
- Asset type `text` (text, fontSize, color, align), rendered in scene and game.
- Pointer input in the game view: `On click`, `Mouse position`, `Mouse button`,
  `Is hovered`, hit-tested against colliders, else sprite/text footprints.
- New nodes: Set/Is enabled, Set text, Is asset, Name of, Equals, To text,
  Join text, Floor/Ceil/Round, Modulo, Random, Time, Restart game.

Tooling: shared CDP harness (tools/harness.mjs), central project registry with
a guard that keeps destructive scripts off the playground (tools/projects.mjs),
plus smoke suites for the demo scene and the jump-and-run game.

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

tools/seed-e2e.mjs

@@ -5,15 +5,12 @@
  * from tools/seed-demo.mjs so the shipped demo can change without rewriting 100+ checks; the
  * fixture's objects are uniquely named and positioned exactly where the checks expect them.
  *
- * Usage: PATH=/opt/node22/bin:$PATH node tools/seed-e2e.mjs <projectId> [baseUrl]
- * Run tools/seed-demo.mjs afterwards to put the demo project back.
+ * Usage: PATH=/opt/node22/bin:$PATH node tools/seed-e2e.mjs [projectId] [baseUrl]
+ * Defaults to the dedicated fixture project; the demo project is refused.
  */
-const projectId = process.argv[2];
-const baseUrl = process.argv[3] ?? 'https://nockal.com/game-maker/';
-if (!projectId) {
-  console.error('usage: node tools/seed-e2e.mjs <projectId> [baseUrl]');
-  process.exit(2);
-}
+import { PROJECTS, cliArgs, writeProject } from './projects.mjs';
+
+const { projectId, baseUrl } = cliArgs('seed-e2e.mjs', PROJECTS.fixture);
 
 /**
  * "Mover" behavior in five nodes: every frame, move the owner along the normalized arrow-key
@@ -93,17 +90,4 @@ const project = {
   ],
 };
 
-const url = `${baseUrl}api/index.php?r=projects/${projectId}`;
-const current = await fetch(url);
-if (!current.ok) {
-  console.error(`GET failed: ${current.status}`);
-  process.exit(1);
-}
-const { revision } = await current.json();
-const res = await fetch(url, { method: 'PUT', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ revision, project }) });
-const body = await res.json();
-if (!res.ok) {
-  console.error('PUT failed', res.status, body);
-  process.exit(1);
-}
-console.log(`seeded ${projectId} → revision ${body.revision}`);
+await writeProject(projectId, baseUrl, project);