fix(spec): correct stale tags restatements in book.json and liveness README

[os-steve]

Fixes#9316

Same class as #9310 (merged as #9317): DocSchema declared tags in 17.0.0 (#4509, ADR-0049) — verified today on origin/main at packages/spec/src/system/doc.zod.ts:126, tags: z.array(z.string()).optional(). That made the book include: { tag } variant live (matchesInclude reads doc.tags, packages/spec/src/system/book.zod.ts:213), but two more places in the liveness tree still restated the pre-fix claim that the tag rule can never match:

• packages/spec/liveness/book.json — the groups.include prop's note (also bumped verifiedAt to today, since the claim was re-checked)
• packages/spec/liveness/README.md — the book row

Both corrected to current-state truth, matching the #9317 wording posture (cites #4509/ADR-0049, cross-references the doc side's fuller history) and preserving load-bearing cross-references — the README row keeps its #4667 inline-translations-tombstone paragraph intact.

No verdict change (include stays status: "live"), no behaviour change — ledger prose only.

Tests

Local gates (worktree objectstack-issue-9316, head e26f5b14a):

• pnpm --filter @objectstack/spec run check:liveness — pass (✓ every governed-type property … is classified … the README state table carries a row for each of the 30 governed type(s))
• pnpm --filter @objectstack/spec run check:empty-state — pass
• pnpm --filter @objectstack/spec run check:strictness-ledger — pass
• pnpm --filter @objectstack/spec run check:variant-docs — pass
• pnpm check:merge-driver — pass (self-test)
• pnpm check:type-source-resolution — pass
• node scripts/check-dev-prereqs.mjs --self-test — pass (the full scan half needs a built workspace and is not run by CI on PRs — only its self-test is, per lint.yml)
• node scripts/docs-audit/check-affected-docs.mjs — pass
• node scripts/check-nul-bytes.mjs --self-test && node scripts/check-nul-bytes.mjs — pass

No changeset — ledger prose only, no user-visible change; docs/qa/platform-checklist/FOLLOW-UPS.md:83 (E1) is an existing append-only decision-register row about the already-merged #9310/#9317 fix (out of this card's file surface, not edited).

Generated by Claude Code

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Generated by Claude Code

[github-actions]

📓 Docs Drift Check

Nothing in this diff resolved to a documentable surface (no symbol, route or SDK anchor derived from 1 changed package(s)), so this run has no opinion about the docs.

What this run could not see

• 2 changed file(s) yielded no anchor (packages/spec/liveness/README.md, packages/spec/liveness/book.json) — pages documenting those are invisible to this run

Coarse fallback — 113 page(s) merely mention a changed package (the pre-#9192 predicate, kept for the deliberately-wide backstop): node scripts/docs-audit/affected-docs.mjs --json origin/main → packageMentionDocs.