feature: the entry point /shared exports the types and constants a server and its web application share.

ADR.md

@@ -118,3 +118,20 @@ Consequences: Every application of the store works on the same rows and refuses
 conflicts, and changes of the tables reach them with a release of the toolkit. The objects' keys
 are in `jsonb`'s order. The store is tested against a real PostgreSQL server, which the release
 workflow does not have, so `npm test` runs on the developer's machine.
+
+## ADR-6: A fourth entry point, /shared, exports the shared types and constants
+
+Status: Accepted
+
+Context: An application keeps the types of its API in one file that its server and its web
+application both import. When those types name types of the toolkit, such as `TfModule`, the file
+must import them from an entry point both sides can resolve: `/server` brings Fastify and `pg`
+into the web application's type check, `/web` brings React and MUI into the server's.
+
+Decision: `shared/index.ts` is the entry point `/shared`, built and exported like the other three.
+It exports the types and constants of `shared/`, the credential types and the types and name
+patterns of the tfvars store, and no code that needs a peer dependency. `/server` and `/web` keep
+exporting them too.
+
+Consequences: An application's shared API types import from `/shared` without the code of either
+side. A type added to `shared/` is exported from `/shared` as well as from the side that uses it.