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

plan/STATUS.md

@@ -235,3 +235,9 @@ interface is MCP, not a cloned GUI. The first storage + MCP slice is done
   entries generate drafts, never posts. Journal events schedule.registered,
   schedule.posted (with the full entry, checked on replay),
   recurring.registered, recurring.generated. No schema change. 59 tools.
+- 2026-10-11: Payouts. books.record_payout grosses a platform deposit up
+  into revenue (by class), fees, and adjustments, refusing unless it
+  reconciles to the cent; it creates a draft so the payout statement is
+  attached as the receipt. Pure core logic (payouts.rs), no new journal
+  events (it journals as a draft and lines). 60 tools. Statement parsers
+  (Apple, Google, Stripe) wait for sample files.