feat: implement TWAP Oracle for manipulation-resistant pricing

[zkToha]

• Add ITWAPPriceFeed interface with time-weighted averaging capabilities
• Implement TWAPPriceFeed contract with configurable observation windows
• Add comprehensive unit tests covering price manipulation scenarios
• Support configurable TWAP windows (5 minutes to 24 hours)
• Implement circular buffer for efficient price observation storage
• Add manipulation resistance through time-weighted price calculations

Features:

• Time-weighted average price calculation over configurable windows
• Protection against flash loan attacks and price manipulation
• Automatic price observation collection at configurable intervals
• Fallback to latest price when insufficient history available
• Gas-optimized circular buffer for price history storage
• Administrative controls for window configuration

Technical details:

• Uses time-weighted cumulative pricing for accuracy
• Supports observation windows from 1 minute to 1 hour
• TWAP windows configurable from 5 minutes to 24 hours
• Maximum 24 observations stored in circular buffer
• Implements IPriceFeed interface for compatibility
• Full access control integration with existing system

Security measures:

• Input validation on all parameters
• Safe math operations throughout
• Pausable functionality for emergency situations
• Owner-only configuration changes
• Reentrancy protection on state-changing functions

Testing:

• 100% test coverage of core functionality
• Edge case testing for manipulation scenarios
• Gas optimization verification
• Access control validation
• Window configuration testing