What problems was I solving

The BigIntString codec was added to @architect/codecs but was never referenced by any caller, test, or downstream package. Keeping it added an unnecessary public export and a stale entry in the generated typecheck manifest.

What user-facing changes did I ship

None. This is an internal dead-code cleanup with no impact on service APIs, persisted data, or UI behavior.

How I implemented it

I deleted architect/codecs/main/bigint-string.ts, removed its wildcard re-export from architect/codecs/main/index.ts, and removed the now-missing main/bigint-string.ts entry from tools/typecheck/typecheck-manifest.generated.json so the typecheck boundary config stays aligned with the actual source files.

Description for the changelog

Removed the unused BigIntString codec from @architect/codecs. The symbol had no consumers or test coverage, and its removal does not change any public API behavior.