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>

level-editor/Cargo.toml

@@ -0,0 +1,46 @@
+cargo-features = ["profile-rustflags"]
+
+[package]
+name = "level-editor"
+description = "Level editor application using the renderer"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[features]
+default = []
+atomics = []
+bulk-memory = []
+
+[profile.release]
+opt-level = "z"
+lto = true
+
+[target.wasm32-unknown-unknown]
+rustflags = [
+    "-Clink-args=--shared-memory",
+    "-Clink-args=--max-memory=1073741824",
+    "-Clink-args=--import-memory",
+    "-Clink-args=--export=__wasm_init_tls",
+    "-Clink-args=--export=__tls_size",
+    "-Clink-args=--export=__tls_align",
+    "-Clink-args=--export=__tls_base",
+]
+
+[dependencies]
+renderer = { path = "../renderer" }
+wasm-bindgen = { workspace = true }
+wasm-bindgen-futures = { workspace = true }
+console_error_panic_hook = { workspace = true }
+log = { workspace = true }
+wasm-logger = { workspace = true }
+web-sys = { workspace = true }
+js-sys = { workspace = true }
+ultraviolet = { workspace = true }
+wgpu = { workspace = true }
+bytemuck = { workspace = true }
+
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = false