Update CI for the 1.0 workspace layout

- rust.yml: modernize (checkout@v4), build/test the whole workspace, add a
  wasm32 core build check and a Node package build+test job. Checks out
  visioncortex next to the repo so the local path dependency resolves.
- python.yml: build crates/vtracer-py (was the deleted cmdapp/); note that
  manylinux builds need visioncortex 0.9.0 published to crates.io.
- release.yml: note the same visioncortex prerequisite for the CLI binary.

.github/workflows/release.yml

@@ -1,5 +1,10 @@
 name: Release
 
+# Builds the `vtracer` CLI binary (crates/vtracer-cli) for each target.
+# PREREQUISITE: the workspace depends on visioncortex 0.9.0; this succeeds once
+# 0.9.0 is published to crates.io and the workspace uses the registry version
+# instead of the local `../visioncortex` path.
+
 on:
   release:
     types: [published]