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-gui/src/pages/parties.rs

@@ -159,6 +159,21 @@ pub fn masked_tin(last4: &str) -> String {
     format!("•••-••-{last4}")
 }
 
+/// A party's taxpayer-ID facts as the viewer shows them: "TIN on file
+/// ••••1234 (SSN)", never more than the last four; once purged from the
+/// vault, "TIN ••••1234 (SSN), purged from the vault".
+pub fn tin_on_file(t: &ledger_core::TinFacts) -> String {
+    if t.vault_record.is_none() && t.purged.is_some() {
+        format!(
+            "TIN ••••{} ({}), purged from the vault",
+            t.last4,
+            t.tin_type.label()
+        )
+    } else {
+        format!("TIN on file ••••{} ({})", t.last4, t.tin_type.label())
+    }
+}
+
 /// Where a party stands on its W-9.
 ///
 /// ```text
@@ -741,6 +756,11 @@ pub fn show_party(ui: &mut Ui, b: &Books, id: PartyId, shell: &mut Shell<'_>) {
             r.context_menu(|ui| widgets::copy_item(ui, "Copy amount", &value.to_string()));
         });
 
+        // A member's page is their capital account statement too.
+        if let Some(st) = b.capital_statement(id, span) {
+            super::capital::capital_card(ui, b, &st, party.label(), &mut go);
+            ui.add_space(14.0);
+        }
         super::columns(ui, 860.0, &[1.0, 1.0], |col, ui| {
             if col == 0 {
                 what_for_card(ui, b, &flow, &label, &mut go);
@@ -882,6 +902,19 @@ fn facts_card(ui: &mut Ui, party: &Party, go: &mut Option<Route>) {
                     &party.id.to_string(),
                 );
                 ui.end_row();
+                k(ui, "Taxpayer ID");
+                match &party.tin {
+                    Some(t) => {
+                        ui.label(RichText::new(tin_on_file(t)).monospace())
+                            .on_hover_text(
+                                "Only the last four digits are in the books; the full number is kept in the encrypted TIN vault, for the CPA package.",
+                            );
+                    }
+                    None => {
+                        ui.label(RichText::new("not recorded").color(p.faint));
+                    }
+                }
+                ui.end_row();
                 if let Some(v) = party.vendor {
                     k(ui, "Vendor record");
                     if widgets::link(ui, RichText::new(format!("vendor {v}")).color(p.accent))
@@ -1141,12 +1174,31 @@ fn entries_card(ui: &mut Ui, b: &Books, info: &PartyInfo, go: &mut Option<Route>
                     let text = if draft { p.muted } else { p.text };
                     let accounts: Vec<String> =
                         e.accounts.iter().map(|a| b.account_name(*a)).collect();
-                    let sub = accounts.join(" → ");
+                    let mut sub = accounts.join(" → ");
                     let kind = if draft {
                         format!("{} · draft", e.origin)
                     } else {
                         e.origin.to_string()
                     };
+                    // Shared with other parties: show their part.
+                    let mut amount = e.amount;
+                    if e.parties.len() > 1
+                        && let Some(mine) = e.parties.iter().find(|x| x.id == info.id)
+                    {
+                        let others: Vec<&str> = e
+                            .parties
+                            .iter()
+                            .filter(|x| x.id != info.id)
+                            .map(|x| x.label.as_str())
+                            .collect();
+                        sub = format!(
+                            "Their share, {} of {}, with {} · {sub}",
+                            super::entry::share_text(mine),
+                            fmt::dollars(e.amount),
+                            others.join(" & ")
+                        );
+                        amount = mine.resolved.map(|v| v.abs()).unwrap_or(e.amount);
+                    }
                     let resp = row(
                         ui,
                         w,
@@ -1155,7 +1207,7 @@ fn entries_card(ui: &mut Ui, b: &Books, info: &PartyInfo, go: &mut Option<Route>
                             (format!("#{}", e.id), 64.0, false, p.muted),
                             (e.description.clone(), 0.0, false, text),
                             (kind, 150.0, false, if draft { p.warning } else { p.muted }),
-                            (fmt::money(e.amount), amt, true, text),
+                            (fmt::money(amount), amt, true, text),
                         ],
                         Some((sub.as_str(), p.faint)),
                         false,