Parties, attachment links, statements, reconciliations (store), TIN vault crate

Parties: one directory for vendors, contractors, customers, employees,
members, platforms, agencies, banks, landlords (ledger-core parties.rs).
W-9/W-4 facts without the number (last four only; any nine-digit run in a
party field is refused, Treas. Reg. 301.6109-4). Vendor and customer
records link to parties on replay; core tags every bill, invoice, payment,
and reversal with its counterparty. Journal events party.*,
entry.party_set; payroll lines name the employee party.

MCP: books.add_party, update_party, set_party_roles, set_w9, set_w4,
parties, party, set_entry_party; draft_entry party; run_payroll employee;
show party. Viewer: Parties directory and party pages, search, journal
text, W-9 attention, demo data.

One definition of a party's money (ledger_core::parties::activity) for
MCP and viewer. 1099 amounts count payments from cash and financing
accounts (a member paying for the company counts; a card doesn't; a
prepayment counts when made): vendor_1099_report_with, B-19.

Store: attachment links to any subject, statements, reconciliations
(schema v11), with replay and projection. ledger-vault: encrypted TIN and
W-9 records (ChaCha20-Poly1305, key file outside the books).

Spec-blind tests for parties (core, store, MCP, viewer) and attachments.

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

crates/ledger-core/src/lib.rs

@@ -27,6 +27,7 @@ pub mod journal;
 pub mod kernel;
 pub mod ledger;
 pub mod money;
+pub mod parties;
 pub mod payouts;
 pub mod payroll;
 pub mod periods;
@@ -49,13 +50,17 @@ pub use assets::{
 };
 pub use classes::{Class, ClassId};
 pub use error::LedgerError;
-pub use form1099::{Form1099, Vendor1099Line, Vendor1099Report, vendor_1099_report};
+pub use form1099::{
+    Form1099, PaymentAccounts, Vendor1099Line, Vendor1099Report, vendor_1099_report,
+    vendor_1099_report_with,
+};
 pub use journal::{EntryId, EntryStatus, JournalEntry, JournalLine};
 pub use ledger::{
     ControlAccount, GENERAL_EXPENSES, Ledger, PAYABLES, PAYROLL, RECEIVABLES, RETAINED_EARNINGS,
     REVENUE, ReconciliationReport, UnclearedLine, control_account, control_accounts,
 };
 pub use money::{Currency, Money};
+pub use parties::{Party, PartyField, PartyId, Role, W4Facts, W9Facts};
 pub use payouts::{Payout, PayoutAdjustment, PayoutLine, PayoutTotals, payout_plan};
 pub use payroll::{PayrollLine, PayrollRun, PayrollRunId};
 pub use periods::{