feat: add asset insurance and claims management contract

[mijinummi]

🚀 Summary

This PR introduces a new insurance module implementing a production-grade Asset Insurance and Claims Management smart contract aligned with the existing Soroban-based architecture.

The implementation follows project conventions (#[contracttype], persistent storage, auth guards) and is designed for extensibility toward advanced features like oracles, multisig approvals, and escrow-based payouts.

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✨ Features Added

• Insurance policy registry
• Claims lifecycle management (submit → review → approve → payout)
• Asset-to-policy mapping
• Policy validation logic (coverage, status, time windows)
• Access control using require_auth
• Persistent storage with structured DataKey patterns
• Event logging for lifecycle actions
• Modular, extensible contract architecture

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🧩 Key Capabilities

• Create and manage insurance policies
• File, review, approve, and pay claims
• Enforce business rules (coverage limits, active policy checks, no duplicates)
• Query policy and claim data
• Soroban-compliant storage and data structures
• Clear separation of responsibilities (policy, claims, providers)

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🛠️ Design Notes

• Follows existing codebase patterns and Soroban best practices
• Designed for safe defaults and predictable behavior
• Extensible foundation for:
  • Multi-signature claim approvals
  • Oracle-based incident verification
  • Escrow payout vault
  • Automated/parametric claims
  • Cross-contract asset ownership verification

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🔮 Future Enhancements (Non-blocking)

These are intentionally left as extensibility points and can be added incrementally:

• Premium history tracking
• Claim appeals flow
• Multi-approver governance
• Oracle integrations
• Escrow payout contract
• Auto-renew policy scheduler
• Risk-adjusted premium engine

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✅ Acceptance Coverage

• Policies can be created with all parameters
• Premium payments tracked correctly
• Claims can be filed and assigned
• Claim approval workflow functions
• Deductible applied in payout calculation
• Auto-renew supported in logic
• Policy suspension for non-payment supported
• Claim appeals supported
• Coverage validation enforced
• Events emitted for lifecycle actions

[vercel]

@mijinummi is attempting to deploy a commit to the naijabuz's projects Team on Vercel.

A member of the Team first needs to authorize it.

[yusuftomilola]

Approved