feat(invoices): allow BAS class 1-3 posting-account overrides and complete the aktiekapital note (#1121)

- invoice/article posting-account overrides accept active class 1-3 accounts;
  class 1-2 (balance-sheet) accounts are rejected on VAT-bearing lines so the
  ruta 05 tax base always books to a 3xxx account
- shared posting-account regex across server schemas, pending-operation
  re-validation, and client forms
- share-capital settings (aktiekapital/antal_aktier) feed the annual-report
  note; kvotvarde derived per ABL 1 kap 6 $; all-or-nothing pair constraint
- signed per-rate VAT breakdown on credit-note PDFs; U+2212 to ASCII hyphen

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

DECISIONS.md

@@ -310,4 +310,11 @@ One line per decision: `[YYYY-MM-DD] <decision>: <why>`. Appended by agents and
 [2026-07-23] Validate preview-PDF payment settings before fetching customer data using the requested currency and document type: this preserves the same exemption semantics while minimizing personal-data processing for requests that cannot render.
 [2026-07-23] Retain an exact pending delivery snapshot when the provider succeeds but the terminal evidence RPC cannot be confirmed, and keep it outside the preparing-only reservation lock: inventing a sent state would be unsafe, while immutable payload, PDF, operator warnings, and later explicit resend availability preserve evidence and recovery.
 [2026-07-23] Keep the invoice-delivery DPIA as a documented screening rather than fabricating a full Article 35 assessment or DPO sign-off: the screened processing does not meet the high-risk threshold, and the implemented controls minimize routine access while preserving statutory evidence.
+[2026-07-23] Invoice PDFs normalize the sv-SE U+2212 minus to ASCII hyphen-minus and retain signed per-rate VAT values: standard PDF fonts can drop U+2212, and absolute VAT groups make deductions and credit notes fail to reconcile with their rows.
+[2026-07-23] Invoice-line and article account overrides accept active BAS classes 1-3 while retaining the legacy revenue_account wire and database field: balance accounts cover deposits, advances, and genuine customer outlays without a migration or API break; classes 4-8 remain excluded so the invoice editor does not become an unrestricted journal editor, and reverse-charge/export mappings remain mandatory.
 [2026-07-23] Derive kvotvärde (aktiekapital / antal_aktier) in the annual-report note instead of adding the kvotvarde column the builder used to read: a stored third value could desync from the other two and file an internally inconsistent Bolagsverket note; ABL 1 kap 6 § makes it purely derived.
+[2026-07-23] Class 1-2 posting overrides are rejected on VAT-bearing invoice lines (INVOICE_CREATE_POSTING_ACCOUNT_VAT_CONFLICT) instead of narrowing the schema back to 3xxx: keeps the deposit/advance feature while guaranteeing the tax base for ruta 05 always books to a revenue account (ML 17 kap 24 §).
+[2026-07-23] The posting-account regex now lives in one shared constant (lib/invoices/posting-account.ts) imported by server Zod schemas, pending-operation re-validation, and both client forms, so the layers cannot drift.
+[2026-07-23] Declined the compliance-swarm suggestion to add DROP COLUMN kvotvarde to the share-capital migration: the column never existed in any migration, so there is nothing to drop.
+[2026-07-23] Kept the missing-aktiekapital annual-report path as a warning rather than a hard block on generation: users must be able to preview an in-progress arsredovisning; the warning surfaces in the wizard/validation before filing, and no placeholder text lands in the filed PDF.
+[2026-07-23] Declined moving ArticleForm's class 1-3 account filter server-side: the chart of accounts is company-scoped and non-sensitive, the authoritative gate is server-side at booking time, and the combobox intentionally sees the full chart for the activate-account flow.