feat(mcp): void, control check, payment method and reference (P4b S1, part B)

books.void_document voids an invoice or bill that should never have
existed by reversing its own entry with the reason (refused while a
payment stands on it, naming that payment). books.control_check ties
receivables and payables to their documents (B-23, B-38 INVARIANT 1):
balance, documents' total, lines that are no document's, the documents
needing attention; books.verify checks the identity and books.digest
lists its problems (control_problems). books.receive_payment and
books.pay_bill take instrument (tagged in the same call) and reference
(in the description), and answer the document's derived remaining and
status. The books record payments; they never collect or make them
(D-45). Docs, handbook and STATUS; the over-the-wire test
documents_void_and_tie_out_over_the_wire; the happy-path journey covers
both tools' output schemas. The processor fee waits for S6.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

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); 118] = [
+pub const TABLE: [(&str, Needs); 120] = [
     ("books.handbook", R),
     ("books.start", R),
     // Settings are committed at once: the settings commit of the plan.
@@ -165,6 +165,8 @@ pub const TABLE: [(&str, Needs); 118] = [
     ("books.create_bill", P),
     ("books.receive_payment", P),
     ("books.pay_bill", P),
+    ("books.void_document", P),
+    ("books.control_check", R),
     ("books.ar_aging", R),
     ("books.ap_aging", R),
     ("books.set_fx_rate", W),