feat(audit): books.audit, the attestation tools and the CPA gate (P8)

The whole re-audit through the tools: books.audit previews its checks, then
with the preview's digest runs them, files the workpaper and journals the
run; the same books, day and scope return the run that exists.
books.attest_receipt, books.review_entry and books.attest_period record a
named client's claim with its self-reported method; books.attestations
weighs each against policy.attestation_bar as it stands. Under
policy.cpa_package_requires_audit = refuse, books that declared audits
cannot export the CPA package without a counted audit for the handoff at the
current head unless a reason is given, which is journaled as a decision
(D-9). Needs attention asks for the month-end attestation, the annual audit
and the audit before the handoff. Rules B-45, the handbook section, the
interface, parity, receipt-store and testing records, and the As-built
block. Merge needs no go-ahead: the live books refuse the new writes until
the owner gives it.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-mcp/src/scopes.rs

@@ -56,7 +56,7 @@ const C: Needs = PostWhenConfirmed;
 const K: Needs = PostForApprovalRules;
 
 /// Every tool and what it needs (INVARIANT 1).
-pub const TABLE: [(&str, Needs); 134] = [
+pub const TABLE: [(&str, Needs); 140] = [
     ("books.handbook", R),
     ("books.start", R),
     // Settings are committed at once: the settings commit of the plan.
@@ -203,6 +203,14 @@ pub const TABLE: [(&str, Needs); 134] = [
     // P5
     ("books.journal_history", R),
     ("books.preview_entry", R),
+    // P8: audits and attestations (an audit previews, then runs; a claim
+    // that someone checked is a write, not a post).
+    ("books.audit", C),
+    ("books.workpaper", R),
+    ("books.attest_receipt", W),
+    ("books.review_entry", W),
+    ("books.attest_period", W),
+    ("books.attestations", R),
 ];
 
 /// What `tool` needs, given its arguments; None for a tool this server