docs: add demo GIF or video to README

[AegisX-dev]

Context

Forma v1.3.1 is now live and Open Source. While the current README explains the architecture and features in text, it lacks a visual walkthrough of the user experience.

The Problem

New visitors, recruiters, and potential contributors cannot immediately see how the application functions without cloning the repo or visiting the live link. We need a "quick preview" directly in the documentation.

Acceptance Criteria

We need a high-quality visual asset added to the README.md (under a new "Demo" or "Preview" header):

Application Demo GIF/Video
Record and embed a short GIF (or MP4) showing the core user flow:

1. Inputs: Briefly showing the selection of biometrics/constraints.
2. Generation: The loading state (animations).
3. Result: The final Plan Card appearing and the exercise details.

Style Requirements:

• Cleanliness: Keep the desktop/browser clean (no cluttered bookmarks or tabs).
• Aesthetic: The recording should showcase the "Refined Brutalism" design (Dark Mode).
• Tools: Recommended tools include Screen Studio, Loom, or OBS.

Deliverable

• Upload the file to the repo (or host it) and embed it using standard Markdown image syntax ![Demo](link-to-gif) in the README.md.