Update README to include SVG demos

I've added an interactive terminal demo to your README using [dg](https://github.com/DeepGuide-Ai/dg). It walks through a sample command execution to show how the tool works. What this PR includes An embedded, recorded terminal demo in the README .dg/ configuration folder and a GitHub Action for CI validation (optional) No changes to logic or runtime code From [deepguide.ai](https://deepguide.ai/)