docs(scripts): check-role-word's --update moves the baseline in both directions (#10042)

The header said `--update` "expands the baseline, which is the shrink-only
direction of this ratchet". The relative clause had no correct antecedent, and
the concept behind it was imprecise either way: `--update` is not directional
at all.

Mechanically it rewrites the baseline from the current tree and never reads the
old ledger (`const baseline = ...` sits after the `update` branch's
`process.exit(0)`), so the ledger moves whichever way the tree moved — shrinking
where the word is gone, EXPANDING where it is new, in one stroke. Only POLICY
separates the two: the baseline is shrink-only, so ratcheting down is the
author's own remedy while expanding weakens the gate and is a maintainer's call.

The header now says that, in the vocabulary this file already uses at the #8435
block (L64-66) and in newUseMessage() (L128-130), and it states that the
self-test and the #8435 farm sweep pin the marker's WORDING, not the act — so
the sentence no longer implies an enforcement that does not exist.

Comment prose only: no verdict, population, exit code or message text changes.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XqDQYVU5smx29ts9pAErja

Author: claude

scripts/check-role-word.mjs

@@ -26,9 +26,15 @@
 //   node scripts/check-role-word.mjs [--update]
 //   node scripts/check-role-word.mjs --self-test   # verify the checker's own rules
 //
-// `--update` expands the baseline, which is the shrink-only direction of this
-// ratchet — the NEW-use message marks that path `⛔ MAINTAINER-ONLY` per the
-// #8435 convention, and the self-test holds the marker in place.
+// `--update` rewrites the baseline from the current tree — it never reads the
+// old ledger (see the `update` branch at the bottom) — so it moves whichever
+// way the tree moved: shrinking where the word is gone, EXPANDING where it is
+// new. Only policy tells those apart. The baseline is shrink-only, so
+// ratcheting down is the author's own remedy, while expanding WEAKENS the gate
+// and is a maintainer's call: the NEW-use message marks that path
+// `⛔ MAINTAINER-ONLY` per the #8435 convention, and the self-test holds the
+// marker in place. Both pin the WORDING, not the act — the flag takes either
+// direction from whoever runs it.
 //
 // Scope: content/docs (hand-written; references/ is generated from spec and
 // excluded — the spec source is the fix site there) and skills/. File and