Show HN: An interactive Qiskit Playground with in-browser circuit visualization

Hi HN,

I've been looking for a way to quickly prototype simple Qiskit circuits without the friction of a local Python setup, so I decided to build a tool for it.

This is a browser-based playground that not only runs your Qiskit code but helps you truly understand what it's doing through visualization.

The key features are the interactive simulations:

- Step-by-step animations: You can watch exactly how the statevector evolves as each gate in your circuit is applied.

- Customizable inputs: Instantly change the initial state (e.g., from |00⟩ to |10⟩) and re-run the simulation to see how it affects the outcome.

- “X-Ray" inspection: Click on any point between gates to inspect the statevector in the middle of the computation, not just at the end.

This is very much an alpha preview. To get it out quickly for feedback, it only supports a limited set of the most common gates (H, X, CNOT, measure, etc.). My goal right now isn't perfection, but to validate if a tool like this is useful for the community.

The backend runs the Python code in a secure sandboxed environment, executes it with the Qiskit library, and then sends the circuit data and simulation results back to the frontend for visualization.

I would be incredibly grateful for your feedback. Is a tool like this useful? What are the most important Qiskit features or gates you'd need for it to be part of your workflow?