BILL-5588: Add descriptor_code support to bank account verification

[kevinpjones]

Description

Problem: Stripe's Setup Intents API added a descriptor code-based microdeposit verification path alongside the legacy two-amount path. When a bank account is created via Setup Intents, Stripe sends a single $0.01 deposit whose statement descriptor contains a 6-character code beginning with SM. The Java SDK had no support for this path.

Solution:

• Added descriptor_code (String) as an alternative to amounts on BankAccountVerify, with mutual-exclusion validation via isValid() and pattern enforcement (^SM[a-zA-Z0-9]{4}$) on the setter
• Added microdeposit_type field to BankAccount response model so callers can determine which verification path applies before calling verify
• Fixed pom.xml: removed defunct ossrh pluginRepository entry (s01.oss.sonatype.org is decommissioned) and removed <extensions>true</extensions> from nexus-staging-maven-plugin so it no longer blocks local builds as a build extension

Non-breaking: All existing code using amounts continues to work without any changes.

Story

https://lobsters.atlassian.net/browse/BILL-5588 (subtask of BILL-5581)

Related PRs

Mirrors lob/lob-php#192

Verify

• Code runs without errors
• 158 unit tests pass (mvn test -Dgroups="Unit")

[gemini-code-assist]

Code Review

This pull request introduces support for verifying bank accounts using a descriptor code in addition to microdeposit amounts. It adds the microdeposit_type field to the BankAccount model and the descriptor_code field to the BankAccountVerify model, along with corresponding validation logic, unit tests, and integration tests. The feedback highlights a potential breaking change where removing the default initialization of the amounts list in BankAccountVerify could cause NullPointerExceptions for existing clients. It is recommended to restore the default initialization, update the validation logic to check for non-empty lists, and precompile the regular expression pattern for the descriptor code to improve performance.

Important

The consumer version of Gemini Code Assist on GitHub is being sunset. Starting June 18, 2026, new organization installations will be blocked, and all code review activity will officially cease on July 17, 2026.
For more details on the timeline and next steps, please review the Help Documentation.