What problems was I solving

The IntString codec in @architect/codecs was completely unused — it had zero imports across production code, tests, and tooling. Keeping it added unnecessary surface area to the shared codecs package.

What user-facing changes did I ship

None. This is a non-breaking internal cleanup with no consumer-visible or runtime behavior changes.

How I implemented it

Deleted architect/codecs/main/int-string.ts and removed its barrel re-export from architect/codecs/main/index.ts. Existing related codecs such as NumberString and BigIntString remain unchanged.

Description for the changelog

Removed the unused IntString codec from @architect/codecs. The symbol had no callers anywhere in the monorepo, so this is a safe, non-breaking dead-code cleanup with no API or runtime impact.