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-gui/src/pages/entry.rs

@@ -51,7 +51,9 @@ pub fn detail(ui: &mut Ui, b: &Books, e: &EntryInfo, shell: &mut Shell<'_>) {
                     }
                 };
                 widgets::pill(ui, e.origin, p.muted, p.hover);
-                if let Some(v) = &e.vendor {
+                if let Some(v) = &e.vendor
+                    && e.party_id.is_none()
+                {
                     widgets::pill(ui, &format!("{} {v}", icon::STOREFRONT), p.muted, p.hover);
                 }
                 if e.missing_receipt {
@@ -85,6 +87,26 @@ pub fn detail(ui: &mut Ui, b: &Books, e: &EntryInfo, shell: &mut Shell<'_>) {
                     shell.go(Route::Entry(r));
                 }
             }
+            if let Some(party) = e.party_id.and_then(|id| b.ledger.get_party(id)) {
+                ui.add_space(4.0);
+                if widgets::link(
+                    ui,
+                    RichText::new(format!(
+                        "{} {}",
+                        super::parties::party_icon(party),
+                        party.label()
+                    ))
+                    .color(p.accent),
+                )
+                .on_hover_text(format!(
+                    "The party this entry is with ({}): open them",
+                    super::parties::roles_text(party).to_lowercase()
+                ))
+                .clicked()
+                {
+                    shell.go(Route::Party(party.id));
+                }
+            }
             if let Some(&asset) = b.entry_assets.get(&e.id) {
                 ui.add_space(4.0);
                 if widgets::link(