UX: first-time learning curve — the flow is simple but needs first-use guidance

[rubenhensen]

Observed in the July 2026 user test (participant 1).

The user described the flow as "nice and simple" but said it takes practice the first time, and low vision made it harder: "It was clear, but the first time you really need to practice."

Direction: add first-run guidance/onboarding — a short walkthrough, inline hints, or a guided first send — to smooth the initial experience.

Part of #288.