v1.0.0 — Time tracking that ends in an invoice

Most timers are good at counting and bad at billing. Span is built backwards from the invoice.

• A week as a grid of projects × days, filled in place, with one running timer at a time
• Rounding and rate live on the client, with a per-project override where reality demands it
• Invoice lines generated from tracked time, ready to hand over
• CSV export for everything else
• Three languages, light and dark themes, one Go binary with SQLite