Source files organization (what ships vs what doesn't)

Question

Determine what belongs in src/ vs what doesn't. The convention: src/ holds what ships and nothing else. The test suite, build scripts, and documentation are not shipped and do not belong there.

Inside src/, mirror the deliverable's own structure. For larger codebases, separate layers explicitly: user-facing entry points (CLI, HTTP handlers, UI) apart from domain logic, and both apart from persistence and external service adapters.

Decision needed: For each package, identify what is the "deliverable" that ships vs. what is internal/tooling/test. This is especially important for a monorepo where some packages are libraries (ship via npm) and others are applications (ship as binaries/Docker images).

Label: wayfinder:task
Part of #2517
Blocks: #2518

Start by inventorying each package's current src/, test suite, build scripts, and documentation, then identify whether its deliverable ships via npm, as a binary, or as a Docker image. For each package, document what belongs in src/ and how its entry points, domain logic, persistence, and external adapters should be separated; done means every package has an agreed deliverable boundary.