Design review: stable core size and package boundaries

[aatuh]

Context

api-toolkit is positioned as small Go HTTP API building blocks. Before adding or promoting more stable root packages, this issue asks for external review of whether the stable core is the right size.

Review paths

• README.md
• ROADMAP.md
• docs/stable-core.md
• docs/core-readiness.md
• docs/package-classification.tsv
• VERSIONING.md

Questions

• Which root packages should be considered the default adoption path for an existing net/http or chi service?
• Are any stable or compatibility-only packages too broad for the root module?
• Which packages should stay stable but be documented as advanced or migration-shaped rather than recommended?
• Which surfaces should move to contrib, app-owned code, or a future module split in a major release?

Desired outcome

A clear recommendation to keep, shrink, or reclassify the stable-core package set before future API additions.