UI improvements Bug fixes

Overtone now works in the classroom as well as the practice room. FOR TEACHERS AND STUDENTS • Assignments: teachers set practice, exercises, theory drills or a sight-reading test and share them as a link or QR code. No accounts needed. • Works for band directors and private teachers alike. A student can follow both at once. • A student dashboard shows what's due and how far along you are. • Practice reports: a PDF of your practice with a seal and a QR code that lets your teacher check it's genuine. • A gradebook for teachers to collect results. • Onboarding asks if you use Overtone for school, and sets it up for students or teachers. NEW TOOLS • Sight-reading: melodies that sound like real music, graded like school festival sight-reading. Overtone listens and marks every note for pitch, timing and length. • Theory drills: notes, key signatures, intervals, chords and scales, with the answers played back on your instrument. • Your year in practice: a recap of your 2026, arriving in early December. LOOKS AND FEELS BETTER • Light theme, alongside System and Dark. • Liquid Metal: a new accent style. • Redesigned layouts for iPad, in portrait and landscape. • A proper launch screen instead of a few seconds of black. FIXES • The tuner stays usable with the metronome running loud. • The metronome keeps playing when you leave the app, so its Lock Screen activity works again. • The screen stays on while you practise. • Tools open faster. • Sight-reading no longer marks on-time notes as late.