refactor: change verification registry getters to return Option and u…

[ABEEGOLD]

Closes #349

##Summary

Context & Problem

Single-entity read-only query getters across the contract inconsistently handled "not found" scenarios:

• ProjectRegistry::get_project, ReviewRegistry::get_review, DisputeRegistry::get_duplicate_dispute, TimelockManager::get_action, and AdminManager::get_proposal returned Option<T> (returning None for missing entities).
• CollectionRegistry::get_collection and VerificationRegistry::get_verification, get_verification_record, get_renewal_request, and get_assigned_admin returned Result<T, ContractError> (returning Err(ContractError::...) for missing entities).

This inconsistency forced SDK/client consumers and frontend indexers to handle different lookup semantics for each single-entity query method.

Solution

Standardized all single-entity getters exposed via lib.rs and their module implementations to use Option<T>:

• Found: Returns Some(entity)
• Not Found: Returns None (without throwing an on-chain contract error)

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Detailed Changes

1. Smart Contract Core Logic

• collection_registry.rs:
  • CollectionRegistry::get_collection now returns Option<Collection>.
• verification_registry.rs:
  • VerificationRegistry::get_verification -> Option<VerificationRecord>
  • VerificationRegistry::get_verification_record -> Option<VerificationRecord>
  • VerificationRegistry::get_renewal_request -> Option<VerificationRenewalRecord>
  • VerificationRegistry::get_assigned_admin -> Option<Address>
  • Internal state mutation functions (approve_verification, reject_verification, revoke_verification, assign_verification, update_verification_evidence, approve_renewal, reject_renewal, is_verification_expired) updated to use .ok_or(ContractError::VerificationNotFound) when fetching records internally.
• admin_manager.rs:
  • Updated proposal execution branches for verification updates to handle Option<VerificationRecord> with .ok_or(...).
• lib.rs:
  • Updated contract entrypoints get_collection, get_verification, get_verification_record, get_renewal_request, and get_assigned_admin to match Option<T> return signatures.

2. Test Suite Updates

Updated unit test assertions to match Option<T> (unwrap(), Some(...), None) across test suites:

• src/tests/collections.rs
• src/tests/renewal.rs
• src/tests/verification.rs
• src/tests/verification_features.rs
• src/tests/verification_assignment.rs
• src/tests/invariants.rs
• src/tests/multisig_and_history.rs
• src/tests/auth_matrix.rs
• src/tests/atomicity.rs

3. Documentation

• CONTRACT_INTERFACE.md:
  • Added an explicit Single-Entity Getter Convention section documenting Option<T> semantics across all single-entity lookups.
  • Updated parameter tables, return values, and code examples for get_collection, get_verification, get_verification_record, get_renewal_request, and get_assigned_admin.

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Breaking Changes Notice

Warning

API Signature Change for SDK Clients:
Query getters get_collection, get_verification, get_verification_record, get_renewal_request, and get_assigned_admin now return Option<T> instead of Result<T, ContractError>. When querying non-existent entities, clients will receive null/None instead of a contract error response.

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Verification & Testing

Automated Test Execution

Run the unit test suite:

cd dongle-smartcontract
cargo test

Results:

test result: ok. 500 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out

WASM Build Verification

Build WASM contract target:

cargo build --target wasm32-unknown-unknown --release