ci: ratchet the role-word baseline for approvals.mdx (5 → 9)

#3113 (docs P1 wave 2) added four `role` mentions to the approvals page
and left the ADR-0090 D3 vocabulary ratchet red — main's Lint & Type
Check has failed on every commit since.

The new occurrences are the class the ratchet's own docstring exempts
("many are legitimate — the better-auth boundary"): they document
`sys_member.role` (a real better-auth membership tier) and the
`type: 'role'` approver type, precisely to teach authors NOT to put a
position name there. That is boundary documentation, not vocabulary
drift, so the baseline moves rather than the prose.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: os-zhuang

scripts/role-word-baseline.json

@@ -3,7 +3,7 @@
   "content/docs/ai/index.mdx": 2,
   "content/docs/api/error-catalog.mdx": 1,
   "content/docs/api/wire-format.mdx": 1,
-  "content/docs/automation/approvals.mdx": 5,
+  "content/docs/automation/approvals.mdx": 9,
   "content/docs/automation/hooks.mdx": 1,
   "content/docs/concepts/architecture.mdx": 4,
   "content/docs/concepts/metadata-lifecycle.mdx": 1,