Assesses the proposed server-held edit state + SignalR live-edit channel against
the current stateless design. Recommendation: don't do the full rewrite now (it
adds stateful-server/scaling/reconnect complexity for a single-editor back-office
flow); instead add a stateless inv/calc endpoint that reuses the backend pricing
(InvoiceSetPricing/VAT) so the editor stops duplicating the math — capturing the
real value without sockets. Add SignalR later only as transport if real-time
co-editing becomes a genuine requirement.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
