docs: update README component table, add CHANGELOG link, complete SEC…

[Ademiitura]

Updated README.md component table to include all 20+ exported components,
added CHANGELOG.md link in the header, and completed SECURITY.md with
responsible disclosure process, contact method, and supported versions.

Description

Three documentation issues have been fixed:

1. README.md ## Components section now lists all exported UI components with brief descriptions
2. Added CHANGELOG.md badge/link in the README header
3. SECURITY.md now includes a responsible disclosure process, contact method for vulnerability reports, and a supported versions table

Related Issues

Closes #186

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Testing

• Component renders correctly
• Tests added or updated for this change
• No console errors or warnings
• Lint passes (npm run lint)
• Build succeeds (npm run build)
• Manual testing completed

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

Screenshots (if applicable)

N/A — documentation changes only.

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You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

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