Desktop: Render overlays with vello (#2965)

* Render overlays with vello

* Fix nix flake comments

* Rendering refactor with better names and code location

* Remove unnecessary overlay renders

* Post rebase fix

Cargo.lock

@@ -1836,16 +1836,19 @@ version = "0.1.0"
 dependencies = [
  "bytemuck",
  "cef",
+ "derivative",
  "dirs",
  "futures",
  "glam",
  "graph-craft",
+ "graphene-std",
  "graphite-editor",
  "include_dir",
  "ron",
  "thiserror 2.0.12",
  "tracing",
  "tracing-subscriber",
+ "vello",
  "wgpu",
  "wgpu-executor",
  "winit",
@@ -1880,6 +1883,7 @@ dependencies = [
  "spin",
  "thiserror 2.0.12",
  "tokio",
+ "tracing",
  "usvg",
  "vello",
  "wasm-bindgen",