[codex] Fix Sonar accessibility and test findings

[igorsatsyuk]

What changed

• fixed Sonar-reported accessibility issues in the Angular audit dashboard and login form by adding explicit input identifiers and labels
• replaced deprecated Kafka JSON serializer usage and preserved producer override binding behavior in command-service
• removed test reliance on the system clock and replaced flagged numeric month literals in backend tests

Why

These changes clean up the Sonar findings shown in the report without changing product behavior, while keeping the Kafka producer configuration and test suite stable.

Impact

• fewer accessibility warnings in the frontend templates
• no deprecated Spring Kafka serializer in command-service
• more deterministic backend tests

Validation

• mvn -pl command-service,audit-writer-service,common/shared-contracts,event-store-service,query-service -am "-Dsurefire.failIfNoSpecifiedTests=false" "-Dtest=KafkaProducerConfigIntegrationTest,AuditLedgerContractGanacheTest,BlockchainWriterServiceTest,JwtSecurityComponentsTest,EventPersistenceServiceTest,IntegrityCheckIntegrationTest,AuditEventDtoMapperTest,AuditLogQueryServiceTest" test