Fixes to video playback on Raspberry Pi 2 and Pi 3

Anthias 2026.06.1 brought video back to the 32-bit Raspberry Pi 2 and Pi 3 image, and it played worse than it should in several ways. Anthias 2026.06.3 fixes them.

• A portrait or 4:3 clip was stretched to fill the screen. It is now scaled to fit and centered, with black bars around it.
• A clip shorter than its time in the playlist restarts each time it ends, and every restart froze on the last frame for up to several seconds on a Pi 3, so the clip looked cut off or late. It now loops without a gap.
• Video at 50 or 60 frames per second stuttered, because these boards draw about 40 frames per second at 1080p. Such clips now play at an even 30 fps. Clips at 30 fps or lower play as they are.
• A clip whose sound couldn't play, for example with HDMI audio turned off or an AC3 soundtrack, failed to play at all. It now plays without sound.

The 64-bit boards use a different video player and aren't affected.