Export nameable procedure definition types

[replitom]

Why

River's procedure constructors return a branded type whose public inferred declarations can expose the internal __BRAND_DO_NOT_USE property. Downstream packages with declaration emit enabled therefore cannot give exported procedure definitions and instantiated service maps stable public names without manually widening them.

What changed

• Add public ProcedureDefinition and exact ProcedureDefinitionMap aliases while preserving the existing brand representation and constructor assignability.
• Export the existing schema-map and instantiated service-map types from the package root.
• Add a consumer declaration-emit regression test covering constructor assignability, exact procedure keys, payload preservation, public service-map naming, and absence of the internal brand name in the consumer declaration.

Downstream use depends on publishing a new @replit/river release and then bumping the consuming package's River version. This PR does not patch any consumer's node_modules.

Versioning

• Breaking protocol change
• Breaking ts/js API change

~ written by Replit ჻

[replitom]

Closing after measuring the result: this did not produce a large enough improvement in the developer experience to keep.