StefanandClaude Opus 4.8
af445c015e
Move the invoice draft editor to a backend single source of truth: an in-memory InvoiceDraftSession (per-token, cached) holds the editable payload, server-computed sums/VAT and validation, plus an automatic change history. The browser posts single edits; the server recomputes and signals the editing session over a dedicated SignalR hub (DraftPreviewHub) to re-fetch. This reverses the previously-documented stateless editor (EVAL_live_invoice_editing, INVOICE_LIFECYCLE §10), by explicit product decision — captured in ADR 0006 and 0007 plus the live-draft-editing concept doc. Backend (this milestone): - InvoiceDraftSession + ChangeHistoryEntry data holders - InvoiceDraftCalculator: pure port of quantChange/invSumUpdate (§13b, VAT-by-rate) and consistency checks — fully unit-tested - IInvoiceDraftCache/InvoiceDraftCache: in-memory store with idle sliding TTL - IInvoiceDraftService/InvoiceDraftEditService: open (payload or DB reload), patch, build state, flush via existing RegisterInvoiceAsync (no new persistence), preview from cache, discard (DB reload), history - InvoiceDraftExpiryService: pre-expiry warning + eviction-with-reason - DraftPreviewHub + IDraftNotifier/DraftNotifier: targeted draftReady/draftExpiring/ draftClosed signals per draft token - inv/dopen|dstate|dpatch|dpreview|dsave|dhistory|ddiscard|dclose endpoints; save reports success/failure via the existing EventService - DI + hub mapping in Program.cs Frontend (additive foundation): $fis.draft SignalR client for /draftpreview. The editor DOM inversion (routing deltas, rendering from server state) is the next, separately-verified step; existing endpoints are unaffected. Tests: 30 new (calculator, cache, expiry, patch/history, flush); 306 total passing. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>