feat: crud-pricing initial implementation

Complete CRUD service for AWS pricing operations - single source of truth.

Features:
- Dual pricing model (retail + account-specific with auto EDP/PPA detection)
- Get/Put pricing operations with intelligent caching
- AWS Pricing API integration for public list prices
- AWS Cost Explorer integration for account-specific pricing
- Access counting for self-learning 14-day refresh
- Query most-accessed instances (powers smart refresh)
- TTL: 30 days (retail), 7 days (account-specific)

Architecture:
- All other lambdas use this for pricing operations
- No direct DynamoDB access from other components
- Consistent schema enforcement
- Complete IAM setup for Pricing API, Cost Explorer, STS

Infrastructure:
- Complete Terraform configuration
- Full CI/CD pipeline (Jenkinsfile)
- Comprehensive documentation
- Production-ready scaffolding

Part of Phase 1 - foundation for pricing system.

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

Co-Authored-By: Claude <noreply@anthropic.com>

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