Force a single TypeScript identity for vendored @intx/types (#457)

Bun overrides already point install-time resolution at vendor/intx-types,
but a nested published @intx/types@0.2.2 under @intx/agent can still give
tsc a second type identity (missing PendingOperation.kind and related
shapes). Pin tsconfig paths at the vendor source so local typecheck
matches CI regardless of that layout, and document both layers.

Author: TheGreatAxios