What is the adjective (jargon) for one-to-one relationship between source and destination?

You can use single source. In the documentation world, it means that one source file can generate every needed output format.

Single-sourcing is the use of a single document to produce other forms of documents, such as manuals and online help. It allows one document to be used in different kinds of formats, thereby increasing the usability of the documentation. Single-sourcing also eliminates duplicate work and facilitates the reuse of existing information, which saves time and money. Single-sourcing is also known as single source publishing.

From Techopedia.