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-mcp/handbook/control-roles.md

@@ -2,4 +2,4 @@
 
 - Invoices, bills, payroll, and closes post to the account filling each role (receivables, revenue, payables, general expense, retained earnings, payroll expense and withholdings); books.roles lists them.
 - A role uses its default code (1200, 4000, 2000, 6999, 3999, 6100, 6110, 2110-2150) until it is assigned one of the chart's own accounts with books.assign_role (journaled). If the chart uses a default code for a different kind of account, the engine refuses and says which. It can't tell an account of the right type but another purpose (a hosting expense at payroll's 6100): check books.roles before running payroll, bills, or invoices.
-- Never assign roles or renumber the human's accounts on your own: explain the conflict, and when they decide, assign the role to their account (best: their numbering stays) or books.renumber_account the account (its history stays).
+- Never assign roles or renumber the human's accounts on your own: explain the conflict, and when they decide, assign the role to their account (best: their numbering stays) or books.renumber_account the account (its history stays); books.rename_account changes only its name, never a role.

crates/ledger-mcp/handbook/settings-and-conventions.md

@@ -8,6 +8,7 @@ The books keep their own record of how they are kept. Every agent, anywhere, rea
 - Change settings with books.set_setting: one or more {key, value} together, with who decided (decided_by) and when (decided_on, default today). A value is checked and kept in one spelling; null clears a key back to its default. Change a setting when the human tells you a company fact or decides a policy, when a tool refuses naming a setting, when books.settings or books.digest lists a problem, and after books.renumber_account lists config_mentions.
 - The company's EIN is the one identity number the settings keep; it is shown masked. No other setting, note or convention ever holds a full TIN: those go only into the vault (the parties-and-tins section).
 - company.timezone sets what "today" means for the books.
+- policy.require_tax_category is warn (unset: a revenue or expense account without a tax category is created, and the result and Needs attention say so) or refuse (books.add_account, books.import_chart_csv and books.set_tax_category won't leave one without; the accounts invoices, bills and payroll create are never refused, and their results name them). Before setting refuse, categorize with the human every account books.digest lists in uncategorized_accounts.
 - books.export_settings writes the settings out as a settings file (TOML), each with who decided it. It is a copy: editing it changes nothing.
 
 ## Books that still read a settings file

crates/ledger-mcp/handbook/tracing-figures.md

@@ -1,6 +1,7 @@
 # Tracing figures
 
 - Reports are pure functions of the posted entries. When the human questions a figure, trace it to its entries with the tools: the report (books.trial_balance, books.profit_and_loss, books.balance_sheet, books.cash_flow), then books.search_entries and books.get_entry for the entries behind it, and books.show to put them on the human's screen.
+- A report without dates covers the fiscal year to date, everywhere (the report tools, the export, books.show and the viewer); one with only an end date covers that date's fiscal year to it. {period_rule} The IIF is never a period: every posted entry from the first through its as_of. Every result names the dates it covers: say them when you quote a figure, and pass dates whenever the human means another period.
 - A cash flow line names its entry (books.cash_flow: each line's entry, kind and accounts). An expense a member paid personally (or equipment a lender paid for) is cash borrowed and spent on its date: a financing line and an operating (or investing) line, each with on_behalf, the part no bank account moved; the reimbursement is a repayment. A noncash disclosure is an entry that moved no cash at all (property contributed, debt converted to capital). A warning names an entry whose later payment or collection the books can't classify, with the fix. A role refusal names the setting to change.
 - Never guess, and never look for the books' files: the tools are the evidence.
 - books.verify checks the books end to end when a number looks wrong or a human asks whether the books are intact.

crates/ledger-mcp/handbook/viewer.md

@@ -1,4 +1,5 @@
 # The viewer
 
 - The human usually has the read-only viewer open beside you. When they ask to see something, and after you post, call books.show so it's on their screen: an entry, an account register, a report for any dates (by month, quarter or year, against the prior period or year), a receipt or document, an asset, a party, a reconciliation, or a search.
+- books.show says which dates it showed (without dates, the fiscal year to date; a register opens on it too, with "Show all dates" one click away for the human). It refuses a start after the end, and options its target ignores (dates for an entry, a split for the trial balance, a start for a report as of a day, a split into more than 240 columns): pass only what the target takes.
 - The viewer never changes the books; every change goes through these tools.