Lumen 0.3.5

Performance — your photos are just there when the app opens

Measured frame-by-frame against a 67,676-photo library, the launch path was redesigned:

• The launch loading state is gone. The window appears with a fully populated grid — thumbnails included — within a frame or two. Previously a "Loading your photos…" spinner sat on screen for ~1.4 seconds.
• New binary library cache: decoding 67k photos went from 410ms to ~100ms. Your existing cache migrates automatically on first launch.
• Sorting, stats, and search indexes are all precomputed in the background, overlapping the window construction time — and the first screenful of thumbnails is pre-warmed into memory before first paint.
• The loading indicator now only appears when loading genuinely takes long (first scan, cold NAS).