docs: enhance CLAUDE.md with AWS Backup-specific guidance (#186)

* feat: migrate from Dependabot to Renovate for better Terraform support

* docs: enhance CLAUDE.md with AWS Backup-specific guidance

- Add comprehensive AWS Backup-specific testing framework documentation
- Include backup-specific development patterns for audit frameworks
- Add organization backup policy management patterns
- Include multi-vault architecture patterns with cross-region support
- Add VSS backup configuration guidance for Windows workloads
- Include security patterns for vault encryption and compliance
- Add performance and cost optimization patterns
- Include comprehensive example configurations for various use cases
- Add backup-specific testing strategies with retry logic for AWS APIs
- Include compliance and audit framework development guidance

* security: fix critical security vulnerabilities in CLAUDE.md

- Replace hardcoded AWS account IDs with dynamic references
- Enhance cross-account policy validation to prevent wildcards
- Add IAM permission validation against dangerous actions
- Enforce encryption by default with AWS managed keys
- Use tag-based resource selection instead of wildcard ARNs
- Enable major provider updates with manual approval

Co-authored-by: Luis M. Gallardo D. <lgallard@users.noreply.github.com>

* docs: fix remaining security and performance issues in CLAUDE.md

- Replace wildcard ARN pattern with secure tag-based selection in VSS example
- Add performance documentation for nested flatten() operations
- Improve documentation clarity with comprehensive resource selection guide

🛡️ Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Luis M. Gallardo D. <lgallard@users.noreply.github.com>

* security: enable major provider updates with approval workflow in renovate.json

- Enable major terraform-provider updates with dependency dashboard approval
- Add manual approval workflow to prevent unauthorized major updates
- Fixes security risk of blocking critical provider security patches
- Resolves critical issue identified in security bug hunt

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Luis M. Gallardo D. <lgallard@users.noreply.github.com>

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Co-authored-by: claude[bot] <209825114+claude[bot]@users.noreply.github.com>
Co-authored-by: Luis M. Gallardo D. <lgallard@users.noreply.github.com>

Author: lgallard