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

docs/spec/sources/intuit-iif.md

@@ -79,6 +79,31 @@ SHA-256 of `IIF Import Kit/IIF Header Help/!ACCNT.htm`: `91b5cbcc90b3b251b467448
 
 Cited (not quoted): a subaccount's NAME includes its parents' names, highest level first. Accounts are identified by NAME; the account number (`ACCNUM`) is a separate, optional column.
 
+### IIF Header Help: Class list (CLASS)
+Retrieved: 2026-10-22 (the kit above, unchanged: same SHA-256)  
+SHA-256 of `IIF Import Kit/IIF Header Help/!CLASS.htm`: `de8a89aac069946583ed1fec7b9042162343b5b34146fb456d17851bccca0ff8`
+
+Cited (not quoted, but for the lines below): the Class list's keyword is CLASS; of its columns (NAME, and TIMESTAMP and REFNUM in export files only) the page says:
+
+> Only the NAME column is required.
+
+> If the class is a subclass of another class, the name includes the name of the parent classes, beginning with the highest level class. If you are creating an import file, use a colon (:) to separate subclass names.
+
+So a class's NAME, like an account's, is one level per colon: the books, whose classes have no parents, write a colon in a class's name as '-', as in an account's (rules.md B-34 rule 8). The page states no length limit and nothing about case.
+
+### IIF Example Files: list declarations
+SHA-256 of `IIF Import Kit/IIF Example Files/QB 2007 & Enterprise 7.0 and later/Import First - List Declarations (Not Version Specific).iif` (the same bytes in each version's folder): `13c730b23bcb8c142621b04206e3628241d83051442c9b14ea2416d21163439c`
+
+Cited (not quoted): a file named "Import First", declaring the lists (accounts, classes, names) that the transaction examples use; its class rows, transcribed (each `→` one tab; the trailing empty fields left out):
+
+```text
+!CLASS→NAME→REFNUM→TIMESTAMP→HIDDEN→DELCOUNT
+CLASS→Class Name→2→1154540261→N→0
+CLASS→Owner→1→1154540254→N→0
+```
+
+The kit's `2004 Deposit (Income).iif` (`IIF Example Files/QB 2004 & Enterprise 4.0/Deposit/`) (SHA-256 `82a5d0efbdeb9440a81e48fa1675355e37d2d78650a026c87caa640d0955ffdf`) names the declared class "Class Name" in the CLASS column of its SPL line, its TRNS line's left empty: a line's class is the one it names, per line. So a class is declared in a `!CLASS` list before the transactions that name it, as accounts are (the Import Manual and `journal.zip`'s read-me, above and below: lists first, or default types are assumed). The books write the one required column, NAME.
+
 ### IIF Example Files: QB 2007 & Enterprise 7.0 and later, General Journal Entry
 SHA-256 of `IIF Import Kit/IIF Example Files/QB 2007 & Enterprise 7.0 and later/Journal Entry/2007 General Journal Entry.iif`: `78917e0f848f38b55f0f1bbde16ef19b9144132a2b21f11831ff29b2ba549879`
 
@@ -157,6 +182,29 @@ Not Intuit, for the record: a third-party IIF vendor answering on Intuit's commu
 
 No Intuit source says what an IIF journal import does with an A/R or A/P line that has no NAME (refuses it, imports it, or asks). So the books write no NAME (writing names would need the customer and vendor lists declared too, with a name unique across them) and the package README names the entries with an A/R or A/P line, so the CPA can add the name in QuickBooks if it asks (rules.md B-34 rule 7).
 
+## How long a class's name may be
+
+Searched 2026-10-22. Intuit's limits article (above) has no row for a class; its `!CLASS` header help states none. Intuit's .NET SDK reference gives QuickBooks Desktop ("QBW") 31 characters for the names of its other lists (`Account.Name`, above; `Item.Name`, `Term.Name`, `JobType.Name`, `CustomerType.Name`), but for a class its only page, `Department.Name` (<https://static.developer.intuit.com/sdkdocs/qbv3doc/ippdotnetdevkitv3/html/d658b447-b3f9-26f1-3a65-e213cfe3c379.htm>, retrieved 2026-10-22, SHA-256 of the retrieved page `9a33e3cbed97cea28558c8530b6d4950b54346ab8f8581897f1a333b072b026d`), describes "User recognizable name for the Class" with "QBW: 1024": a page for departments (a QuickBooks Online list) whose wording names classes, so not taken as Desktop's class limit.
+
+### Intuit's qbXML Onscreen Reference: `ClassAdd`
+Source: the QuickBooks Desktop SDK's Onscreen Reference (OSR), <https://static.developer.intuit.com/qbSDK-current/common/newosr/index.html>, whose `ClassAdd` request page is drawn from <https://static.developer.intuit.com/qbSDK-current/common/newosr/qbsdk/json/ClassAddRq.json>  
+Retrieved: 2026-10-22  
+SHA-256 of the retrieved `ClassAddRq.json`: `760505a11638ccdb3ea30a9714fa02651509660291ae4eff09e20d4942a310de`
+
+The request's `Name` element (required, a string, `"xmlNameHtml" : "Class-Name.html"`) carries the OSR's length limits per edition:
+
+> "maxCA" : 31, ... "maxUK" : 31, "maxAU" : 31, ... "maxDT" : 31, ... "maxOE" : 100
+
+So 31 characters for a class's name in every QuickBooks Desktop edition the OSR covers (the US desktop, Canada, the UK and Australia), 100 only in Online Edition ("OE"). The same reference's `AccountAddRq.json` (retrieved the same day, SHA-256 `856c64ea3aeea8229692f98cdcfe32278cc9070c56bff7eed74d9e53702c3a40`) gives an account's `Name` the same figures (31 in each Desktop edition, "maxOE" : 100), matching the limits article's Account Name 31 and the .NET reference's "QBW: Max=31", so the fields read as Desktop's own limits.
+
+Not Intuit, for the record: Conductor's QuickBooks Desktop API reference (a service over QuickBooks Desktop's own SDK, which mirrors the OSR), "Create a class", <https://docs.conductor.is/api-ref/qbd/classes/create.md>, retrieved 2026-10-22, SHA-256 of the retrieved file `8588c0ffaa7d5082abd0329734a00ee42179894109ec7572a66d7f844e908d89`, of a class's `name`:
+
+> The case-insensitive name of this class. Not guaranteed to be unique because it does not include the names of its hierarchical parent objects like `fullName` does.
+
+> Maximum length: 31 characters.
+
+So the books hold a class's NAME to 31 characters, as an account's own level (Intuit's own limit for a class, above), and keep no two alike ignoring case (Conductor: case-insensitive; rules.md B-34 rule 8).
+
 ## What QuickBooks does with an over-long name (not Intuit)
 Source: Thomson Reuters, Accounting CS help, "Export payroll journal entries", <https://thomsonreuters.com/en-us/help/accounting-cs/integrate-data-with-other-applications/export-payroll-journal-entries>  
 Retrieved: 2026-10-20