P3: rename accounts, one set of period defaults, tax categories warn or refuse (defects 15, 16, 8)

books.rename_account; account names trimmed, bounded, refused when a
sibling's or TIN-shaped; books.show refuses what its target ignores. A
report asked for without dates covers this fiscal year so far, everywhere
(one rule for tools, descriptions and the viewer; the IIF and CPA package
keep their own dates). policy.require_tax_category warns or refuses; a
Form 4797 gain is shown apart on every return.

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

crates/ledger-package/src/lib.rs

@@ -35,8 +35,8 @@ pub use books::PackageBooks;
 pub use iif::export_iif;
 pub use package::{Package, PackageRequest, build_package, package_file_name};
 pub use reports::{
-    Settings, bs_statement, cash_flow_for, cash_flow_statement, member_capitals, pnl_statement,
-    report_members, report_meta, statement_range, year_earnings,
+    Settings, as_of_date, bs_statement, cash_flow_for, cash_flow_statement, member_capitals,
+    pnl_statement, report_members, report_meta, statement_range, year_earnings,
 };
 pub use text::{csv_escape, money, parse_date, share_text};
 pub use tins::{TinSource, tin_kind, tin_type_key, vault_tin};