Shared parties with exact shares, member capital statements, TINs for any party, K-1 worksheet

Entries may name several parties, each with an exact amount, a percent,
or a share derived from the members' capital lines or [[company.members]]
shares (entry.parties_set); shares always sum exactly. The 1099
worksheet counts a vendor's share. A member's party page is their
partner capital statement, from the same ledger_core::k1 source as the
CPA package.

books.set_tin stores any party's TIN (members' SSNs for K-1s) in the
vault (party.tin_set, last four in the books). The CPA package carries a
K-1 member worksheet (k1-members.csv, with a members' total that ties to
Schedule L) and the 1099 worksheet with full TINs, saved outside the
books only. files_jointly_with notes spouses' two K-1s land on one 1040.

Adversarial review fixes: reversed contributions no longer inflate K-1
contributions and distributions; a K-1 row never takes another party's
TIN; TIN detection covers dot/slash/dash separators; refusals redact
TINs; vendor tagging can't silently replace shared parties; reversals
follow re-apportioning.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GWVo7x3UHw5kwCUaWxiejX

crates/ledger-cli/src/main.rs

@@ -270,18 +270,22 @@ fiscal_year_start = "01-01"
 # Members of a multi-member LLC, one block each: shares come from the
 # operating agreement (IRC §704(a)), "50%" or "0.5", summing to 100%. Each
 # names a capital account in the chart, and optionally a distributions
-# account that a close zeroes into capital.
+# account that a close zeroes into capital. Spouses who file one joint
+# return each name the other in files_jointly_with (each still gets their
+# own K-1; the CPA package notes both go on one Form 1040).
 # [[company.members]]
 # name = "Alex Rivera"
 # share = "50%"
 # capital_account = "3000"
 # distribution_account = "3100"
+# files_jointly_with = "Sam Chen"
 #
 # [[company.members]]
 # name = "Sam Chen"
 # share = "50%"
 # capital_account = "3001"
 # distribution_account = "3101"
+# files_jointly_with = "Alex Rivera"
 
 [books]
 # The books' data, relative to this file. The tools take it from --data-dir