Let the scene view hide symbols, names and shapes per asset kind

The scene view gets crowded once a scene holds many behaviors,
colliders and tilemaps. A new eye button in the topbar opens a list of
all placeable asset kinds, and each row has toggles for what the scene
view draws for that kind.

- The popup lists all 9 placeable kinds from Behavior to Tilemap, with
  the columns Symbol, Name and Shape. It stays open while switching.
- Sprite, Text and Tilemap draw no symbol, so their symbol toggle is
  greyed out. Their name toggle shows a new centred name tag, which is
  off by default.
- Shape exists for Collider and Tilemap. A hidden collider outline is
  neither drawn nor clickable. A hidden tilemap shape removes the
  collision outlines and the paint tint, the tiles stay visible.
- A hidden symbol takes no slot in the ring and draws no dashed link to
  its parent. A name that stays on moves to the centre of the object.
- The setting lives in the project as `sceneVisibility`, not in
  localStorage. Older projects load with the defaults, which match the
  view as it was.
- Switching has no undo step, like the game scale. It only changes the
  view. A change made during Play survives Stop.
- The rules sit in `src/core/model/sceneVisibility.ts`, the popup in
  `src/editor/panels/SceneVisibilityPopup.ts`. Four new SVG icons.

Not covered by a check: symbol off with name on for a kind with a
symbol, Text and Tilemap with names, and the paint tint with shape off.

Tests:
- ./check.sh: 173 files, 2515 tests, CHECK EXIT 0
- e2e 46: ALL PASSED, 17 checks. 46g clicks the popup, lays a small
  tilemap over the crate and removes it again.
- e2e 8 alone on a fresh seed: ALL PASSED, 23 checks. A red check in
  the partial run 2,8,46 came from the module selection.
- 8 new unit tests in tests/editor/scene-visibility.test.ts.
- 4 counter-probes, each fails its test: load ignores the saved value,
  Play skips the saved model, scene view ignores collider shape, scene
  view ignores tilemap shape.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/model/Project.ts

@@ -8,6 +8,7 @@ import {
 } from './Asset';
 import { DEFAULT_LAYER_NAME } from './collisionLayers';
 import { DEFAULT_GAME_SCALE, DEFAULT_PLAY_FROM, type GameScale, type PlayFrom } from './playSettings';
+import { defaultSceneVisibility, type SceneVisibility } from './sceneVisibility';
 import { DEFAULT_SYMBOL_SCALE } from './symbolScale';
 
 /** 2: a placed container carries no copy of its template. */
@@ -47,6 +48,8 @@ export interface Project {
   playFrom: PlayFrom;
   /** The scale the game view draws the camera at. Saved, but not an undo step: it is how you look. */
   gameScale: GameScale;
+  /** Which symbols, names and collider outlines the scene view shows, per type. Saved like `gameScale`. */
+  sceneVisibility: SceneVisibility;
 }
 
 export function createEmptyProject(id: string, name: string): Project {
@@ -62,6 +65,7 @@ export function createEmptyProject(id: string, name: string): Project {
     symbolScale: DEFAULT_SYMBOL_SCALE,
     playFrom: DEFAULT_PLAY_FROM,
     gameScale: DEFAULT_GAME_SCALE,
+    sceneVisibility: defaultSceneVisibility(),
   };
 }