Extensions

Rust SDK (extensions/rust-sdk): Defines the OrbitronPlugin trait, plugin metadata, and a backend SDK facade (OrbitronSdk) for loading, measuring, rendering, and applying delta updates. The plugin loader is still gated behind experimental-plugins.
Python bridge (extensions/python-bridge): PyO3 bindings that wrap the service layer for notebooks, scripts, and downstream automation. Program-neutral result access includes Scene.dipole_moment(), Scene.excited_states(), Scene.brillouin_zone(), Scene.residues(), Orbitron.task_summaries(path), and Orbitron.analyze_bond_orders(scene). Builder-facing methods include Scene.from_smiles(), Scene.molecular_electronic_state(), and Scene.set_molecular_electronic_state(). See §9.1 for architecture and usage.
The trunk demo page (viewer/wasm/index.html + app.js), built by trunk build into viewer/wasm/dist/. This is the development harness — the steps below exercise it.
The <orbitron-viewer> custom element (viewer/wasm/ts/src/orbitron-viewer.ts), bundled by npm run build in viewer/wasm/ts (esbuild) to the committed viewer/wasm/orbitron-viewer.js. This is the one that ships: the desktop File > Export > Web View, the Python export_html, and Scene._repr_html_ all embed it alongside the wasm shim and binary.

So a change under viewer/wasm/src needs trunk build for the demo page and the staging script (which runs both trunk and esbuild) before anything that embeds the element picks it up.

Wasm viewer scaffold

To sanity-check the pipeline:

Additional notes: - The wasm shell is being split into smaller modules under viewer/wasm/src/wasm (e.g. delta parsing, selection handling, overlay label helpers). Keep new changes localized to these modules and update viewer/wasm/src/wasm/mod.rs when adding files.

Generate a SceneGraph payload using the release CLI and visible scratch space:

mkdir -p ~/scratch/orbitron-wasm
conda run -n orbitron-dev cargo build --release -p orbitron-cli --bin orbitron
ORBITRON_CLI=target/release/orbitron \
  conda run -n orbitron-dev python viewer/wasm/scripts/generate_scene_bin.py \
    io/pipelines/tests/fixtures/xyz/benzene.xyz \
    ~/scratch/orbitron-wasm/scene.bin

Build and serve the wasm app with the scene on the same origin:

cd viewer/wasm
conda run -n orbitron-dev trunk build --release
cp ~/scratch/orbitron-wasm/scene.bin dist/scene.bin
cd dist
conda run -n orbitron-dev python -m http.server 8081 --bind 127.0.0.1

Load the scene bytes:
```
http://127.0.0.1:8081/?scene=/scene.bin
```