Condense README and add learning-only disclaimer

[Copilot]

README was verbose (250 lines) and lacked explicit disclaimer about educational purpose.

Changes

• Reduced from 250 to 44 lines (82% reduction)
• Added prominent disclaimer at top: "⚠️ Note: This repository is for learning purposes only"
• Simplified content structure:
  • Condensed features to bullet points
  • Removed detailed Rust concept explanations (10+ subsections)
  • Removed architecture diagrams, security notes, future enhancements
  • Kept only: basic installation, usage instructions, and high-level learning focus
• Added learning emphasis in footer

The README now immediately communicates educational intent and provides only essential information.

Original prompt

Modify readme.md and make it short and add this repo is only for learning puposes.

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