separate out renderer crate (#13)

* add keyboard handler

* some cleanup

* add l key binding

* Fix WASM shared memory generation for Rust nightly 2025-10-20+

Add explicit linker flags for shared memory generation after Rust PR #147225
removed automatic flags with +atomics. This fixes DataCloneError when sharing
memory with workers.

Changes:
- Add --shared-memory, --max-memory, --import-memory flags
- Export TLS symbols: __wasm_init_tls, __tls_size, __tls_align, __tls_base
- Update both Cargo.toml and package.json build scripts

Amp-Thread-ID: https://ampcode.com/threads/T-41d99b69-5754-4fdf-b06e-a46343fa7485
Co-authored-by: Amp <amp@ampcode.com>

* add a level-editor crate

* remove redundant worker setup

* simplify app setup

* add SceneBuilder

* separate out default scene implementation in a crate

* define default method for MeshBuilder

---------

Co-authored-by: Amp <amp@ampcode.com>

renderer/src/platform/web/mod.rs

@@ -0,0 +1,16 @@
+use wasm_bindgen::JsCast;
+
+pub mod worker;
+
+pub fn get_canvas_element(selectors: &str) -> web_sys::HtmlCanvasElement {
+    let window = web_sys::window().unwrap();
+    let document = window.document().unwrap();
+    let element = document.query_selector(selectors).unwrap().unwrap();
+    let canvas = element.dyn_into::<web_sys::HtmlCanvasElement>().unwrap();
+    let scale_factor = window.device_pixel_ratio();
+    let width = (canvas.client_width() as f64 * scale_factor) as u32;
+    let height = (canvas.client_height() as f64 * scale_factor) as u32;
+    canvas.set_width(width);
+    canvas.set_height(height);
+    canvas
+}