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

plan/served.md

@@ -899,6 +899,7 @@ The first company keeps working between phases.
 - **Description.** Tool text (S:2202) is corrected.
 - **Proof.** Lean `cashflow_sections_sum_to_cash_change` in `Statements.lean`, derived from the per-entry balance law. Property test (5,000 cases). Kani on the section-sum kernel function.
 - **The first company.** FY2026 must foot (it didn't: its figures are in the company's private change log); the golden is recomputed by hand.
+- **As built (2026-10-20).** `ledger-core/src/cashflow.rs` (re-exported from `reports`), the kernel's `take`, `apply_cash`, `entry_flows`, `constructive` and `exchanged`. The section rule is refined by ASC 230-10-50-5 ("only the cash portion"): each entry's cash is applied to the sections moving against it, operating, investing, financing, each up to its own movement (CONVENTION: the order), and the rest is disclosed (rules.md B-14 rule 3); the plan's wording holds exactly for entries whose cash settles all they move (`prop_pure_entries_sections_are_movements`). D-35's layout (operating by class, an entry's interest its own class; investing and financing by kind with each kind's total, each transaction under its kind), the bill split and the warnings are built; reversals pair along the chain from its root, and exchanges inside one section are disclosed (the review's two highs). What a member or a lender pays or receives for the company is cash borrowed (or contributed) and spent, on its date, per D-42 (rules.md B-14 rule 11, the kernel's `constructive`, Kani `constructive_nets_to_zero` and `constructive_mirrors`, Lean `constructive_nets`, `constructive_neg`): ASC 230 doesn't address it and the firm guides present it so; an expense a member pays into capital is a constructive contribution (BDO 3.4's parent paying a subsidiary's expenses; the K-1 worksheet already calls it cash); property a member owned, the seller's own credit, and interest or guaranteed payments charged to what the company owes stay noncash. D-35's noncash presentation was replaced the same day. The tool text is at `ledger-mcp/src/server.rs` (`books.cash_flow`). The first company's change log is kept with its goldens, outside this repository (5.6).
 
 **Defect 7, IIF** (`ledger-import/src/iif.rs:169,243`): DOCNUM = entry_id. Output encoded in Windows-1252; characters outside it are transliterated (deunicode) and listed in `warnings`.