Roadmap: qualified cross-document references for amendments

[dvejsada]

Roadmap thread for a deferral recorded in spec §18.

Today (v0.1): an amendment imports the definitions of the document it amends (§7.5), but {{ref:}} resolves only within the amendment itself. References to the original's provisions are literal text — "Section 5.1 of the Agreement" — citing the original's executed rendering, with §3.8 advising parties to pin the numbering scheme used at execution.

The candidate: import the original's section identifiers too, with a qualified form such as {{ref: payment-terms, doc=amends}}, validated against the original and rendered per its numbering.

Why it was deferred: the original's rendered numbers are a presentation artifact of whichever numbering scheme was active when it was executed — and LegalDown documents deliberately store no presentation settings. A qualified reference is only correct if the renderer knows the original's executed scheme. Where should that knowledge live: repository configuration, the amendment's render job, an attestation alongside the original, somewhere else?

Use cases, prior art from other document systems, and concrete syntax proposals all welcome.