test: add workspace-level security issue remediation test set

[ayomideadeniran]

Overview

close #335

This Pull Request remediates several critical security vulnerabilities (SECURITY-001, 002, 003) and standardizes protocol-wide event publishing. The changes ensure that the Remitwise smart contract suite is production-ready and fully compliant with the protocol's threat model.

Key Remediations

1. Event Standardization

• Refactored all event emitters across remittance_split, savings_goals, bill_payments, orchestrator, insurance, and family_wallet to use the RemitwiseEvents::emit helper.
• Standardized topic schema: (symbol_short!("Remitwise"), category.to_u32(), priority.to_u32(), action).

2. Security Hardening

• Reporting Authorization: Enforced user.require_auth() in all sensitive query functions to prevent information disclosure.
• Orchestrator Reentrancy Guard: Implemented an execution state lock to block cross-contract reentrancy.
• Emergency Transfer Cooldown: Enforced a mandatory cooldown period and balance checks in family_wallet emergency mode.

3. Stability & Integration

• Synchronized remitwise-common dependencies across the workspace.
• Resolved cascading compilation errors and signature mismatches.
• Deleted redundant local event implementations (bill_payments/src/events.rs).

Verification Results

Full execution of the integration test suite (cargo test -p integration_tests) confirmed a 100% pass rate (16/16 tests). This includes the new test_event_topic_compliance_across_contracts validator.

Documentation

• Updated THREAT_MODEL.md and SECURITY_REVIEW_SUMMARY.md to reflect the mitigated status of critical threats.