New photos get their own progress view

When a drive check finds photos added since the first study, the app now says exactly that: "Studying your new photos", with real counts, instead of replaying the setup stages.

• One clear card, real counts. A single "Adding your new photos" card shows what’s happening and how many photos are left.
• Everything you’ve earned stays. Fun Box, search, and your studied archive stay available throughout.
• No more surprises at launch. Catching up no longer resizes the window or jumps to a showcase year.
• Notifications match, saying "Adding 1,578 new photos" instead of setup-stage numbers.

Polish

• The app is now simply "All Our Years". The "(alpha)" suffix is gone from the name, the Dock, and update prompts.
• Time-remaining estimates round to whole seconds, and the header count stays in step with the progress panel.