guarantees: promise visibility about the surface we do not promise

loom's .usages.md for this page found the hole. The docs site depends on the
command surface — its README and publish script tell a person to type loomctl
external add loom/<repo> <doc>.md — and this page explicitly does not promise it.
Nothing parses the command, which is exactly why no check would catch a rename:
the thing that moved is not a document anybody adopted.

The answer is not to promise the surface, which would freeze the CLI. It is to
promise that a change to it lands on this page — which consumers already lock — so
a rename reports 200 the day it happens. The exclusion goes from "you are on your
own" to "you will be told", and it costs one append-only section.

Same shape as a supersession in the event log: the record is not that the thing
never changes, it is that the change is findable by whoever depended on it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018UTxuSizozEA8yDitPuris

.loom/orientation.md

@@ -61,3 +61,9 @@ Three moves, and each has a document that owns the rule:
 
 - source: https://git.hypertheory-labs.dev/loom/externals/raw/branch/main/.loom/published/externals.md
 - what of ours depends on it: `.loom/externals/git.hypertheory-labs.dev/loom/externals/externals.usages.md`
+
+## This repository publishes
+
+See `.loom/published/`. What is handed over for others to depend on is
+there; the rest of the repository is not hidden, it is simply not what
+anybody depends on.