Staff - Client Party Code Search

As a Registries Staff user, I want to look up party names and codes, so that I can quickly retrieve information for registration and verification tasks.

# Story: Improving Secured Party Code Management in the PPR

The current Secured Party Code Management system in the Personal Property Registry (PPR) needs enhancements to better support both Registries Staff and client users who manage registrations. Improving this system will streamline processes, enhance data integrity, and empower users with more self-service capabilities.

## Staff Use Case

As a **Registries Staff user**, I need robust tools to:
- Look up party names and codes as part of recurring tasks.
- Ensure there are no duplicate names or codes in the system.
- Retrieve contact and ownership details associated with a party code.
- Add new parties and assign codes.
- Add additional codes to existing parties (splitting functionality).
- Consolidate codes across multiple parties into a single party code.
- Apply global changes to multiple registrations efficiently.

These enhancements will allow staff to maintain a clean and accurate registry, supporting operational needs and ensuring high data quality.

No files, tests, or entry points are named. Start by clarifying which part of the Staff party-code search is in scope and locating the existing PPR party-code management entry point; done should be defined by agreed search behavior and acceptance checks.

Written by the indexing model from the issue text.