merge: P4b S7, bad debts (branch S7, 4b4fecb9)

The fourth of the paused branches: Ledger::write_off and the bad_debts
control role, invoice.written_off with its evidence filed in the same
store call, books.write_off_invoice, the write-off on the timeline and
in Needs attention, Lean writeOff_within_bounds, rules.md B-41 and the
bookspec examples. Twenty-eight files conflicted with the S4.4, S5 and
S6 merges; resolved as plan 8.0.2 says, keeping both sides' appends with
their seams restored, and: the scope table at 125; S7's law numbered 37;
B-41 placed before B-42; the handbook's step 4 and recovery procedures
folded into the one invoices-and-bills section; S7's wire tests in their
own module with the confirm S4.4's contract needs; S7's copy of the
payment steps dropped (S6 replaced them with Ledger::settle) and its
write-off journaled through S6's journal_auto_lines; in the old-books
fixture S7's hand-written write-off moved to a second invoice, since
S6's hand-written payment settles invoice 1 in full.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-mcp/src/server_tests.rs

@@ -42,7 +42,7 @@ fn annotations_complete() {
     const D: Hints = (Some(false), Some(true), None);
     const WI: Hints = (Some(false), Some(false), Some(true));
     const DI: Hints = (Some(false), Some(true), Some(true));
-    let table: [(&str, Hints); 124] = [
+    let table: [(&str, Hints); 125] = [
         ("books.handbook", R),
         ("books.start", R),
         ("books.set_setting", DI),
@@ -167,6 +167,8 @@ fn annotations_complete() {
         ("books.access_log", R),
         ("books.backup", R),
         ("books.back_up_now", WI),
+        // P4b S7: a bad-debt write-off.
+        ("books.write_off_invoice", D),
     ];
     let tools = BooksServer::tool_router().list_all();
     assert_eq!(tools.len(), table.len());
@@ -206,8 +208,8 @@ fn annotations_complete() {
             "{name}: openWorldHint"
         );
     }
-    // docs/mcp-interface.md names the 29 destructive tools.
-    assert_eq!(table.iter().filter(|(_, h)| h.1 == Some(true)).count(), 29);
+    // docs/mcp-interface.md names the 30 destructive tools.
+    assert_eq!(table.iter().filter(|(_, h)| h.1 == Some(true)).count(), 30);
 }
 
 /// Every refusal an agent can be given whose text is fixed here, or