Forge state files are located under <app dir>\data\state.

In most cases, these files do not need to be included as part of an application definition. However, when an application uses dimension values from auto-generated or external dimensions, then Forge state files do need to be synchronized across environments. In this situation, the state files contain the IDs of these dimension values and ensure that the same dimension value always gets the same ID no matter how many times Forge is run. These dimension values may be used in a variety of ways, including dynamic business rules, landing pages, dimension ordering, and precedence rules.

In other words, Forge state files should be identified as part of the application definition if the application uses auto-generated dimensions or external dimensions, and values from these dimensions are referenced anywhere in the application configuration (for example, in landing pages or content items, explicit dimension ordering, or in precedence rules).