Spec: the contract everything else cites

A spec is the document later work is checked against. /blueprint plans against it, /e2e-test derives cases from its criteria, and /revise uses it as the scope fence. So it must be product-level, testable, and stably addressable.

The spec says what and why, in user-observable terms. How belongs to /blueprint. The litmus test: two different implementations can both satisfy it. A technical constraint appears only when it is a genuine product constraint, such as compliance or platform.

Required references

Paths are relative to this file. <plugin root> is two directories above it.