M7.1: Classic 3D renderer, cameras, lights, 3D views and camera-tool commands

- render/three_d: camera eval (one/two-node, DOF), default 50mm comp camera,
  orthographic Front/Left/Top/Back/Right/Bottom + perspective Custom Views,
  orbit/pan/dolly rig math; lights (parallel/spot/point/ambient, falloff,
  cone feather) and material shading; per-pixel depth-sorted compositor for
  3D runs (exact intersections, perspective-correct sampling, blend modes,
  track mattes, motion blur), ray-cast planar shadows with transmission and
  diffusion, per-layer DOF blur. RenderOpts.view camera override.
- project: camera iris/highlight props, aperture per comp width, light
  orientation/rotations, two-node auto-orient defaults.
- engine: layer.newCamera/newLight with presets & settings,
  layer.cameraSettings/lightSettings (Layer Settings dispatches),
  view.set3DView + View > Switch 3D View items (F10/F11/F12), last/reset view,
  camera.orbit/pan/dolly, view.get3D; EditorState.views3d.
- demo: "3D Showcase" comp (camera move, key spot + ambient fill, shadows,
  DOF, intersecting planes, gridded floor).
- tests: projection, depth order, intersections, lighting, shadows, DOF,
  views, rig math; command undo/redo. Fix a few pre-existing clippy lints.

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

apps/effectcraft-cli/src/main.rs

@@ -22,7 +22,8 @@ fn open(s: &mut Session, args: &[String]) {
             eprintln!("effectcraft: {e}");
             std::process::exit(1);
         }
-    } else if args.iter().any(|a| a == "--demo") || true {
+    } else {
+        // No project given (or `--demo`): open the demo project.
         let _ = s.execute("file.openDemoProject", json!({}));
     }
 }