docs: improve README with badges, TOC, and quick start

[Gingiris]

What this PR does

Improves the README with better discoverability and onboarding experience.

Why

• Missing badges: The README only had a CI badge. Adding License, Last Commit, and Stars badges helps the project stand out in GitHub search results and gives visitors an instant sense of activity and licensing.
• No Quick Start: New users had to click through to docs/development.md just to find how to run the project. A Quick Start section with actual commands (make setup, bun dev, etc.) reduces time-to-first-run from minutes to seconds.
• No Table of Contents: With 8+ sections, navigating the README required scrolling. A TOC lets readers jump directly to what they need.
• No Features overview: The existing 3 bullet points didn't convey the full scope of the project. A Features table makes capabilities scannable at a glance.

Changes

• Added badges (License: MPL-2.0, Last Commit, Stars)
• Added Table of Contents for easier navigation
• Added Quick Start section with actual setup commands (extracted from docs/development.md and verified against Makefile, .env.example, and package.json)
• Added Features table summarizing key capabilities

All existing content is preserved — these are purely additive changes.

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🤖 This PR was created with AI assistance and reviewed by a human.

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Note

Low Risk
Documentation-only updates to README.md that don’t affect runtime behavior; risk is limited to potential onboarding inaccuracies if commands/prereqs drift from the codebase.

Overview
Adds additional GitHub badges (license, last commit, stars) to improve project visibility.

Introduces a Table of Contents, a Quick Start section with prerequisites and local run commands, and a scannable Features table to improve first-run onboarding and discoverability.

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[Gingiris]

Hi there! 👋 Just checking in — if you have a chance to review this, I'd appreciate any feedback. Happy to adjust anything based on your preferences!