feat: implement comprehensive contract versioning system with data migration support

[Jagadeeshftw]

Description

Overview

This MR implements a comprehensive versioning system for the Predictify contract that enables safe contract upgrades, data migration between versions, and version compatibility validation.

Problem Statement

• No versioning system existed to track contract versions
• No mechanism for data migration between contract versions
• No version compatibility validation
• No upgrade or rollback procedures
• No version history tracking

Solution

Implemented a complete versioning system with the following components:

Core Components

• Version Structure: Tracks major, minor, patch versions with compatibility information
• Version History: Maintains complete version history with timestamps and migration records
• Version Manager: Central manager for all versioning operations
• Migration System: Handles data migration between versions
• Compatibility Validation: Ensures version compatibility before upgrades

Key Features

• Semantic Versioning: Follows semantic versioning (major.minor.patch) standards
• Compatibility Tracking: Maintains list of compatible versions
• Migration Metadata: Tracks migration requirements and breaking changes
• Rollback Support: Enables safe rollback to previous versions
• Version History: Complete audit trail of all version changes

Functions Implemented

• track_contract_version(version: Version) - Track new contract versions
• migrate_data_between_versions(old_version: Version, new_version: Version) - Handle data migration
• validate_version_compatibility(old_version: Version, new_version: Version) - Validate compatibility
• upgrade_to_version(target_version: Version) - Perform version upgrades
• rollback_to_version(target_version: Version) - Rollback to previous version
• get_version_history() - Retrieve complete version history
• test_version_migration(migration: VersionMigration) - Test migration procedures

Technical Implementation

• Storage: Persistent storage for version history and migration records
• Error Handling: Comprehensive error handling for all versioning operations
• Testing: Full test coverage including edge cases and error scenarios
• Documentation: Extensive inline documentation and usage examples

Benefits

• Safe Upgrades: Ensures contract upgrades are safe and compatible
• Data Integrity: Maintains data integrity during version transitions
• Audit Trail: Complete history of all version changes
• Rollback Capability: Quick recovery from problematic upgrades
• Future-Proof: Extensible system for future versioning needs

Testing

• ✅ Unit tests for all versioning functions
• ✅ Compatibility validation tests
• ✅ Migration testing framework
• ✅ Error handling tests
• ✅ Edge case coverage

Files Changed

• contracts/predictify-hybrid/src/versioning.rs - New versioning module
• contracts/predictify-hybrid/src/lib.rs - Integration and function exposure
• contracts/predictify-hybrid/src/errors.rs - Error handling integration

Closes #99

[greatest0fallt1me]

LGTM! @Jagadeeshftw