Add Plan Amendment & Codicil Functions to Inheritance Contract

[ONEONUORA]

Component: Contracts (Inheritance) | Effort: 4-5 days | Priority: MEDIUM

Current State

Plans can be modified but no formal amendment/codicil tracking.

Missing Functions

Amendment and codicil functions:

• create_amendment() - Create formal amendment to plan
• get_amendments() - List all amendments
• get_amendment_history() - Get full amendment history
• revoke_amendment() - Revoke specific amendment
• create_codicil() - Add codicil (minor change)
• get_codicils() - List all codicils

Why This Matters

• Legal validity: Formal amendments required in many jurisdictions
• Audit trail: Track all changes to plan
• Transparency: Beneficiaries see change history
• Compliance: Meet legal requirements for will modifications

Tasks

• Add Amendment struct (amendment_id, plan_id, change_type, old_value, new_value, created_at, reason)
• Add Codicil struct (codicil_id, plan_id, description, created_at)
• Implement create_amendment() function
  • Record what changed
  • Store old and new values
  • Require owner signature
  • Emit AmendmentCreated event
• Add get_amendments() view function
• Implement create_codicil() for minor changes
• Add amendment versioning
• Implement revoke_amendment() function
• Track amendment count per plan
• Add amendment approval by witnesses (optional)
• Add tests for amendments
• Document amendment process

Acceptance Criteria

• Amendments tracked formally
• Change history complete
• Codicils supported
• Amendments can be revoked
• Tests cover amendment scenarios
• Documentation explains legal implications