feat(iif): carry each line's project in CLASS, the classes declared first

The P3 cutover review's open point 1: entries carry projects (classes,
B-37), but the QuickBooks Desktop file (B-34) left the CLASS field empty
on every line, and neither B-34 nor the README said so, though B-34 rule
6 says nothing changes silently.

Intuit's IIF Import Kit (vendored in docs/spec/sources/intuit-iif.md,
the kit's SHA-256 unchanged): the `!CLASS` header help says "Only the
NAME column is required" and a subclass's NAME is its parents' names
first, joined by colons; the kit's "Import First - List Declarations"
example declares `!CLASS` rows before any transaction, and its "2004
Deposit (Income)" example names the class line by line in CLASS. So the
file now declares every class in a `!CLASS` list after the accounts and
before `!TRNS`, and writes each line's class in CLASS (empty where the
line has none). Books with no class write no list, byte for byte as
before. A line whose class wasn't declared is refused
(IifError::UndeclaredClass), never written classless.

A class's NAME follows B-34's rules for an account's own name: plain
ASCII (rule 3), a colon written '-' (it would start a subclass),
trimmed, '?' if nothing is left, cut to 31 characters: Intuit's qbXML
Onscreen Reference gives `ClassAdd`'s Name "maxDT" : 31 (and 31 in the
Canadian, UK and Australian desktop editions; 100 only in Online), the
same as its `AccountAdd` Name (both JSON files vendored by SHA-256);
Conductor's QuickBooks Desktop API reference agrees and says the name is
case-insensitive. Classes whose NAMEs would match ignoring case get
" (id)", round after round, as accounts get " (code)", except that
among names that match, those already written differently from the
books (made safe, or tagged) yield first, a second " (id)" if need be:
a class's own name is kept unless another class's own name is the same
ignoring case (classes 1 "Café", 2 "Cafe", 3 "Cafe (1)" are written
"Cafe (1) (1)", "Cafe", "Cafe (1)"). Each class is tagged twice at most
and ids differ, so none is left alike (a hand-built list is refused). Each class name
written differently is an IifChange (IifField::ClassName), said one
line each in the warnings and in the package README, whose
"written differently" paragraph now names class names' limits; its IIF
line says CLASS is each line's project when there are classes. The MCP
and viewer notes count "account or class name(s)".

API: `iif_classes(ledger)` builds the list; `journal_to_iif` takes it
(`&[]` for none).

Docs: rules.md B-34 rule 8 with its sources; intuit-iif.md (the
`!CLASS` help, the list declarations and deposit examples, Intuit's SDK
department page, the qbXML Onscreen Reference's ClassAdd and AccountAdd
and Conductor's class reference, each with SHA-256);
mcp-interface.md (books.export iif, the package note); the bookspec
example iif-quickbooks-journal-file.toml (two projects: one carried and
renamed, one only declared; every line derived by hand); testing.md;
STATUS (open point 1 done; point 3 waits for the close, the owner said).

Tests: ledger-import
`iif_writes_each_lines_class_and_declares_the_classes_first`,
`iif_class_names_fit_quickbooks_and_every_change_is_listed`,
`iif_class_names_written_as_the_books_have_them_are_kept`,
`iif_refuses_an_undeclared_or_unfit_class`, property
`iif_class_names_never_clash`; ledger-package
`the_package_iif_carries_each_lines_project` and the bookspec example.
Broken to confirm: CLASS written empty fails the two exact-file tests,
the package test and the bookspec example; the " (id)" tag dropped fails
the names test and the property; tagging every name that meets (no
yielding) fails the kept-names test and the property (its shrunk case,
"A-B" beside "A\uFF1AB", kept in the regressions file).

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

crates/ledger-mcp/handbook/cpa-handoff.md

@@ -3,5 +3,5 @@
 - books.export_cpa_package carries every member's and 1099 payee's full TIN from the vault (the K-1 worksheet and the 1099 worksheet). It hands the zip over: run its download command with the folder the human wants it in (books served by `wanderbooks mcp`), then tell them where it is. The viewer's "Export for CPA" makes the same package.
 - Never file the package, or a file from it, into the books.
 - tin_gaps lists each member or payee whose TIN it lacks and why: collect them (books.set_tin, books.set_w9) and export again.
-- Everything in it is as of its as_of: the 1099 worksheet counts the year's payments through that day, and general-journal.iif (the QuickBooks Desktop file) every posted entry from the first through it, closing entries left out. That file is plain ASCII within QuickBooks Desktop's limits: warnings (and the README) say what it writes differently from the books ("Café" as "Cafe", a name cut to 31 characters, a subaccount of another type at the top level, the memos grouped); tell the human. It names no customer or vendor: the README lists the entries on accounts receivable or payable, where QuickBooks may ask the CPA for one.
+- Everything in it is as of its as_of: the 1099 worksheet counts the year's payments through that day, and general-journal.iif (the QuickBooks Desktop file) every posted entry from the first through it, closing entries left out. That file is plain ASCII within QuickBooks Desktop's limits: warnings (and the README) say what it writes differently from the books ("Café" as "Cafe", a name cut to 31 characters, a subaccount of another type at the top level, a project's name as its QuickBooks class, the memos grouped); tell the human. Each line's project is its CLASS, the projects declared first as QuickBooks classes. It names no customer or vendor: the README lists the entries on accounts receivable or payable, where QuickBooks may ask the CPA for one.
 - With members, the K-1 worksheet is two files: k1-members.csv (each member's capital on the books, with their TIN) and k1-tax-basis-capital.csv (the same capital on the tax basis, as Schedule K-1 Item L reports it: property contributed at the member's adjusted basis, IRC §723, a prepaid contract handed over at its book amount for the CPA to confirm, and the reconciliation from book to tax capital). A line the books can't know (the share of income as figured for tax, always; tax depreciation; a disposal's tax gain; the basis of property no asset records) is left open with what the books have: tell the human the CPA supplies it; never fill it in.

crates/ledger-mcp/src/server.rs

@@ -9205,7 +9205,7 @@ impl BooksServer {
         let warnings = package.warnings;
         if package.iif_changes > 0 {
             note.push_str(&format!(
-                " {} account name(s), number(s), place(s) or memo(s) are written differently in general-journal.iif to fit QuickBooks Desktop (warnings says how; so does the README): tell the human.",
+                " {} account or class name(s), number(s), place(s) or memo(s) are written differently in general-journal.iif to fit QuickBooks Desktop (warnings says how; so does the README): tell the human.",
                 package.iif_changes
             ));
         }

crates/ledger-mcp/tests/oracle_mcp.rs

@@ -3586,7 +3586,7 @@ fn cpa_package_holds_the_year_and_its_evidence() {
         assert!(readme.contains(&format!("\n- {w}\n")), "{w} in {readme}");
     }
     assert!(out["note"].as_str().unwrap().ends_with(
-        " 5 account name(s), number(s), place(s) or memo(s) are written differently in general-journal.iif to fit QuickBooks Desktop (warnings says how; so does the README): tell the human."
+        " 5 account or class name(s), number(s), place(s) or memo(s) are written differently in general-journal.iif to fit QuickBooks Desktop (warnings says how; so does the README): tell the human."
     ));
 
     // Receipts: exactly the two behind the rent.