P3: dated 1099 decisions, payment methods and the card exception (defects 23, 12, 18, D-40)

A vendor's 1099 decision is its own dated fact (files NEC or MISC, not
reportable with its reason, or undetermined), applied by each payment's
date. Payment methods are recorded; card and network payments are left
out and listed; a member's check through financing counts; a bank payment
with no method counts (D-40); $2,000 for payments after 2025. One
worksheet for the tool, the viewer and the CPA package.

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

crates/ledger-core/src/error.rs

@@ -522,6 +522,19 @@ pub enum LedgerError {
     #[error("unknown vendor id {0}")]
     UnknownVendor(u64),
 
+    /// A 1099 decision, or the 1099 report, was refused: the message says
+    /// why and what to do.
+    #[error("{0}")]
+    Invalid1099(String),
+
+    /// The payment method named does not exist.
+    #[error("unknown payment method (instrument) id {0}")]
+    UnknownInstrument(u64),
+
+    /// A payment method (instrument) was refused: the message says why.
+    #[error("{0}")]
+    InvalidInstrument(String),
+
     /// The referenced invoice does not exist.
     #[error("unknown invoice id {0}")]
     UnknownInvoice(u64),