P3: the cash flow statement by ASC 230 (defect 1, D-35, D-42)

Direct method with the operating reconciliation and noncash schedules; it
foots by construction (Lean and Kani). Every non-cash account belongs to
one section; reversals net; a member or lender paying for the company is
cash borrowed and spent (D-42, constructive receipt and disbursement);
property a member contributes stays noncash. The bookspec seed: one loader
checks every example.

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

crates/ledger-store/tests/store.rs

@@ -1821,19 +1821,27 @@ fn every_figure_of(l: &ledger_core::Ledger) -> (usize, usize) {
         tally(reports::profit_and_loss_for_period(l, start, end, None).map(|_| ()));
         tally(reports::general_ledger(l, start, end).map(|_| ()));
         tally(reports::members_equity(l, start, end, &members).map(|_| ()));
-        tally(
-            reports::cash_flow(
-                l,
-                &reports::CashFlowParams {
-                    start,
-                    end,
-                    cash_accounts: cash.clone(),
-                    financing_accounts: vec![],
-                    investing_accounts: vec![],
-                },
-            )
-            .map(|_| ()),
+        // The statement of cash flows foots on every book, or is refused
+        // for a reason: never an engine error (rules.md B-14 rule 9).
+        let cf = reports::cash_flow(
+            l,
+            &reports::CashFlowParams {
+                start,
+                end,
+                cash_accounts: cash.clone(),
+                financing_accounts: vec![],
+                investing_accounts: vec![],
+                members: members.clone(),
+            },
         );
+        assert!(
+            !matches!(
+                cf,
+                Err(ledger_core::LedgerError::CashFlowDoesNotFoot { .. })
+            ),
+            "{cf:?}"
+        );
+        tally(cf.map(|_| ()));
         tally(ledger_core::k1::k1_worksheet(l, start, end, &members, &cash).map(|_| ()));
         tally(ledger_core::tax_summary(l, start, end, None).map(|_| ()));
         let _ = reports::cancelled_in_span(l, start, end);