Zero warnings from `cargo clippy --workspace --all-targets`, which is now a hard rule rather than "clean except pre-existing": - ChartOfAccounts::add takes the Account it registers instead of eight loose parameters (too_many_arguments); Ledger::add_account builds it. Same validation, same errors. - close_period tool: collapse the nested if-let into a let chain. - iif.rs docs: the IIF layout example shows tabs as `\t` instead of literal tab characters (tabs_in_doc_comments). - Tests: drop an unused binding; assert! instead of assert_eq! against a literal bool. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01MtYEaR6M6Ybdhm6X98BWNu