fix: bake version into binary at build time

Instead of hacking around the version in the Node.js wrapper script,
properly pass the version at build time via SANDBOX_AGENT_VERSION env var.

Changes:
- build.rs: Generate version.rs with VERSION constant from env var
- main.rs: Use generated version constant for clap --version
- Dockerfiles: Accept SANDBOX_AGENT_VERSION as build arg
- build.sh: Pass version as second argument to Docker builds
- release.yaml: Pass version to build script during CI
- Remove version hack from sdks/cli/bin/sandbox-agent wrapper

The version is now baked into the binary during the release build,
ensuring --version reports the correct npm package version.

docker/release/windows.Dockerfile

@@ -26,6 +26,10 @@ RUN cd frontend/packages/inspector && pnpm exec vite build
 
 FROM rust:1.88.0
 
+# Accept version as build arg
+ARG SANDBOX_AGENT_VERSION
+ENV SANDBOX_AGENT_VERSION=${SANDBOX_AGENT_VERSION}
+
 # Install dependencies
 RUN apt-get update && apt-get install -y \
     llvm-14-dev \