feat: payout gross-up (books.record_payout)

A platform deposit becomes a draft entry with the deposit, fees,
adjustments, and gross revenue (by class), refused unless gross - fees
+/- adjustments equals the deposit to the cent. The payout statement is
attached as its receipt before posting. 60 tools.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu

docs/requirements.md

@@ -140,6 +140,9 @@ requirement conflict, the requirement wins.
   the journal records each posting with its full entry and replay checks
   it. Recurring entries generate drafts only, never posts, so the receipt
   policy always applies.
+- **R-? — Payout gross-up.** Platform deposits are recorded gross:
+  revenue, fees, and adjustments, reconciled to the deposit to the cent,
+  as a draft that carries the payout statement as its receipt.
 - **R-? — A/R and A/P workflows.** Was R-FUTURE-5.
   `ledger-core::arap`: customers, vendors, invoices, bills, payments,
   AR/AP aging. MCP tools for the full workflow.