9. Add authorization pattern audit

[DeFiVC]

What: Audit all authorization patterns for consistency and completeness.

Why: Inconsistent authorization can cause vulnerabilities. Audit ensures security.

Scope: Review all require_auth calls. Verify authorization is correct. Add missing authorization. Standardize patterns.

Acceptance criteria:

• All authorization is reviewed
• Patterns are consistent
• Missing auth is added
• Security is improved

Technical context: All contract source files.

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