feat: prepaid/deferred amortization schedules and recurring entries

Amortization schedules spread a prepaid expense or deferred revenue over
the months it covers, to the cent, posting on month ends; runs preview
first, are idempotent, honor closed periods, and are exempt from the
receipt policy like depreciation. Recurring entries generate drafts only,
never posts. Six new tools (59 total); four new journal events, replayed
and checked.

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

plan/STATUS.md

@@ -229,4 +229,9 @@ interface is MCP, not a cloned GUI. The first storage + MCP slice is done
   and close into it. CloseTo became RetainedEarnings { sweep } / Account
   { into, sweep } / Members([MemberClose]); journals without a target, or
   with the old plain "retained_earnings", still replay.
-
+- 2026-10-11: Schedules. Prepaid expenses and deferred revenue amortize
+  monthly on month ends, to the cent; runs are previewed, idempotent, and
+  exempt from the receipt policy (the schedule is the evidence). Recurring
+  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.