v0.4.3 - Documentation organization

Maintenance release focused on repository presentation and documentation organization.

Changes:

• Moves audit and local-source documents into docs/audits/.
• Moves historical release notes into docs/releases/.
• Documents agents/ in README.md.
• Updates validation for the organized documentation layout.
• Keeps the catalog at 32 skills with no architecture or skill additions.

Validation:

npm ci
npm run check

Expected result:

Skill validation passed.
Generated CATEGORIES.md with 32 skills.
Markdown link check passed.