POC : Railways Migration Enablement (COLIN -> Modernized BR)

**Description:**

The corporation migration framework has been established and is currently used to migrate corporations from the legacy system to the modernized platform using a two-phase migration approach:

Phase 1: Migrate the entity with tombstone data (including basic entity information and a list of historical filings) from COLIN to the BR, enabling the entity to be accessed in the modernized system.
Phase 2: Migrate the complete details of all historical filings associated with the entity.

The objective of this proof of concept (POC) is to leverage this existing migration mechanism to migrate a single non-corporation entity type from the legacy/mainframe environment into the modernized system.

Although the existing migration framework uses a two-phase approach to enable ongoing management of migrated entities in the modernized system, this POC will intentionally select an entity that does not require further management, as its last filing was completed several years ago. This allows the team to validate the migration framework, data mappings, and historical filing migration while minimizing operational complexity. The focus is on ensuring that the migrated entity and its complete filing history are accurately represented, viewable, and searchable in the modernized system.

**Objectives**

- [x] Select an appropriate entity type for the POC. -> Proposed entity type: Railways, which has 5 types of filings
- [x] Reuse the existing corporation migration framework wherever possible.
- [x] Migrate one entity type, including all associated filing history, to the modernized system.
- [ ] Validate that the migrated data is complete, accurate and searchable .
- [ ] Document lessons learned, gaps, and recommendations for future entity migrations.