P3: odd cents split the same running way everywhere (defect 17, D-38)

Members' shares of earnings are split cumulatively by largest remainder in
the closes, the members' equity statement, the K-1 worksheet and the
viewer, so a member's capital on a given day never moves by a cent when its
month is later closed. Old closes replay as they were; the first P3 close
carries any true-up. Feature members_cumulative. Kani and Lean proofs of
the bounded drift; bookspec examples.

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

docs/requirements.md

@@ -63,9 +63,11 @@ requirement conflict, the requirement wins.
   (loss), distributions (debits), ending — plus a total that equals
   balance-sheet equity. Earnings not yet distributed (retained earnings and
   unclosed income) and the period's income are allocated by ownership share
-  to the cent by largest remainder (the odd cent goes to the largest
-  remainder, ties to the earlier member; the owner, 2026-10-13), so every
-  row's total is exact. Any equity change the roll-forward doesn't explain is shown as
+  to the currency's minor unit by largest remainder (the odd cent goes to
+  the largest remainder, ties to the earlier member; the owner, 2026-10-13),
+  earnings not yet closed the way their close will split them (D-38,
+  rules.md B-13), so every row's total is exact and a member's capital on a
+  day never changes when its month is closed. Any equity change the roll-forward doesn't explain is shown as
   "other", never hidden.
 - **R-9d — Tax categories.** Revenue and expense accounts map to stable
   tax categories (`ledger_core::tax::CATEGORIES`: key, label, income /
@@ -127,9 +129,13 @@ requirement conflict, the requirement wins.
   end** (later-dated entries belong to later periods) and puts the net in
   `to`: `CloseTo::RetainedEarnings` (`3999`, the corporate convention;
   `close_period` is shorthand) or `CloseTo::Members` (each member's capital
-  account by share, to the cent, odd cents by largest remainder: the
-  partnership convention; closes journaled before 2026-10-13 replay with
-  the rule they were made under, the last member absorbing rounding), or `CloseTo::Account` (any equity account, e.g.
+  account by share, to the currency's minor unit, odd units by largest
+  remainder, cumulatively from the first members close with these members
+  and shares, so no member is ever a unit from their exact share: the
+  partnership convention, rules.md B-13; closes journaled under earlier
+  rules replay with the rule they were made under: `CloseTo::MembersRun`,
+  the run rule of 2026-10-13 to P3, `CloseTo::MembersPerClose`, and
+  before 2026-10-13 the last member absorbing rounding), or `CloseTo::Account` (any equity account, e.g.
   a sole proprietor's capital). Every target can sweep owner-pay equity
   accounts — draws, distributions, dividends — into it: a member's
   distributions account into their own capital. The members' equity