feat: Implement comprehensive error management system with centralized error handling

[1nonlypiece]

Pull Request Description

📋 Basic Information

Type of Change

Please select the type of change this PR introduces:

• ✨ New feature (non-breaking change which adds functionality)
• 📚 Documentation update
• 🧪 Test addition/update
• 🔧 Refactoring (no functional changes)

Related Issues

Closes #103
Fixes #103
Related to #103

Priority Level

• 🟡 High (significant impact)

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📝 Detailed Description

What does this PR do?

This PR implements a comprehensive, centralized error management system for the Predictify Hybrid contract. It moves all error types from the main lib.rs file into a dedicated errors.rs module, providing better organization, categorization, and debugging capabilities.

Why is this change needed?

The previous error system had all error types scattered throughout the main contract file, making it difficult to maintain, debug, and extend. This centralized approach provides:

• Better code organization and maintainability
• Clear error categorization (Security, Market, Oracle, Validation, State, System)
• Comprehensive error documentation and helper functions
• Improved debugging capabilities with error context
• Modular error system for easier future enhancements

How was this tested?

• All existing tests updated to work with new error codes
• New unit tests added for error categorization, messages, and helper functions
• Manual verification that all error scenarios work correctly
• Test coverage includes error context, recoverability, and criticality checks

Alternative Solutions Considered

• Keeping errors in main file but adding documentation (rejected - doesn't solve organization)
• Using external error libraries (rejected - not compatible with Soroban's no_std environment)
• Simple error enum without categorization (rejected - doesn't provide enough structure)

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🏗️ Smart Contract Specific

Contract Changes

Please check all that apply:

• Existing functions modified
• Error handling improved

Security Considerations

• Input validation

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🧪 Testing

Test Coverage

• Unit tests added/updated
• All tests passing locally
• Manual testing completed
• Edge cases covered
• Error conditions tested

Test Results

# Paste test output here
cargo test
# Expected output: 33 tests passed, 0 failed
running 33 tests
test errors::tests::test_error_codes ... ok
test errors::tests::test_error_context ... ok
test errors::tests::test_error_recoverability ... ok
test errors::tests::test_error_messages ... ok
test errors::tests::test_error_criticality ... ok
test errors::tests::test_error_categories ... ok
test test::test_create_market_with_empty_question - should panic ... ok
test test::test_create_market_successful ... ok
test test::test_create_market_with_empty_outcome - should panic ... ok
test test::test_create_market_with_non_admin - should panic ... ok
test test::test_reflector_oracle_fallback_mechanism - should panic ... ok
test test::test_fetch_oracle_result ... ok
test test::test_reflector_oracle_error_handling - should panic ... ok
test test::test_authentication_required - should panic ... ok
test test::test_dispute_result_insufficient_stake - should panic ... ok
test test::test_dispute_result ... ok
test test::test_fetch_oracle_result_market_not_ended - should panic ... ok
test test::test_fetch_oracle_result_already_resolved - should panic ... ok
test test::test_reflector_oracle_get_price_success - should panic ... ok
test test::test_reflector_oracle_with_empty_feed_id - should panic ... ok
test test::test_reflector_oracle_get_price_with_different_assets - should panic ... ok
test test::test_reflector_oracle_performance - should panic ... ok
test test::test_resolve_market_oracle_unavailable - should panic ... ok
test test::test_resolve_market_before_end_time - should panic ... ok
test test::test_reflector_oracle_integration_with_market_creation - should panic ... ok
test test::test_vote_on_nonexistent_market - should panic ... ok
test test::test_successful_vote ... ok
test test::test_vote_on_closed_market - should panic ... ok
test test::test_resolve_market_oracle_wins_low_votes ... ok
test test::test_vote_with_invalid_outcome - should panic ... ok
test test::test_resolve_market_community_wins_weighted ... ok
test test::test_resolve_market_oracle_and_community_agree ... ok
test test::test_resolve_market_oracle_wins_weighted ... ok

test result: ok. 33 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.25s

Manual Testing Steps

1. Verified error categorization works correctly for all error types
2. Tested error helper functions with various input scenarios
3. Confirmed error messages are human-readable and accurate
4. Validated error context creation and debugging utilities
5. Checked that all existing functionality works with new error system

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�� Documentation

Documentation Updates

• README updated
• Code comments added/updated
• API documentation updated
• Examples updated
• Architecture documentation updated

Breaking Changes

Breaking Changes:

• Error codes have been reorganized and some new ones added
• Error helper functions now return Result<(), Error> instead of panicking directly

Migration Guide:

• Update any external code that depends on specific error codes
• Replace manual error validation with helper functions where appropriate
• Use new error categorization for better error handling logic

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🔍 Code Quality

Code Review Checklist

• Code follows Rust/Soroban best practices
• Self-review completed
• No unnecessary code duplication
• Error handling is appropriate
• Logging/monitoring added where needed
• Security considerations addressed
• Performance implications considered
• Code is readable and well-commented
• Variable names are descriptive
• Functions are focused and small

Performance Impact

• Gas Usage: Minimal impact - error helper functions are lightweight
• Storage Impact: No additional storage requirements
• Computational Complexity: O(1) for error categorization and helper functions

Security Review

• No obvious security vulnerabilities
• Access controls properly implemented
• Input validation in place
• Oracle data properly validated
• No sensitive data exposed

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🚀 Deployment & Integration

Deployment Notes

• Network: Testnet/Mainnet
• Contract Address: N/A (no deployment required)
• Migration Required: No
• Special Instructions: None

Integration Points

• Backward compatibility maintained

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📊 Impact Assessment

User Impact

• End Users: No direct impact - error messages are more descriptive
• Developers: Improved debugging capabilities and error handling
• Admins: Better error reporting and system monitoring

Business Impact

• Revenue: No direct impact
• User Experience: Improved error messages and system reliability
• Technical Debt: Significantly reduced - centralized error management

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✅ Final Checklist

Pre-Submission

• Code follows Rust/Soroban best practices
• All CI checks passing
• No breaking changes (or breaking changes are documented)
• Ready for review
• PR description is complete and accurate
• All required sections filled out
• Test results included
• Documentation updated

Review Readiness

• Self-review completed
• Code is clean and well-formatted
• Commit messages are clear and descriptive
• Branch is up to date with main
• No merge conflicts

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📸 Screenshots (if applicable)

N/A - Backend changes only

🔗 Additional Resources

• Design Document: ERROR_MANAGEMENT.md
• Technical Spec: errors.rs module
• Related Discussion: Error management system requirements
• External Documentation: Soroban SDK error handling patterns

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💬 Notes for Reviewers

Please pay special attention to:

• Error categorization logic and completeness
• Helper function implementations and error handling
• Test coverage for new error system
• Documentation clarity and completeness

Questions for reviewers:

• Are the error categories comprehensive enough?
• Should we add more helper functions for common scenarios?
• Is the error context system sufficient for debugging needs?

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Thank you for your contribution to Predictify! 🚀

[greatest0fallt1me]

Everything checks out! Merging now @1nonlypiece