Orion v0.4.0-alpha.5

A fix release. If you have alpha.4, take this one instead.

Apple silicon only. Ad-hoc signed, not notarized — first launch needs
right-click → Open. README-FIRST.txt inside the disk image says the same.

Fixed

The ⓘ icons next to each panel section now actually show their text. In
alpha.4 they drew correctly and explained nothing — the release notes described
controls that explain themselves on hover, and they did not. The icon was a
plain image carrying the system tooltip modifier, which macOS only honours on a
view that takes part in hit testing. It now has a real hover target, and the
text is drawn rather than handed to the system tooltip, which did not appear at
all on the machine this was tested on.

Everything else is unchanged from alpha.4 — see those notes for perspective
correction, versions, highlight reconstruction, film grain, the creative
vignette, and a brush that no longer slows down as you paint.

Known limits

• Ad-hoc signed, not notarized.
• A spot placed across a hard edge is corrected wrongly on both sides — it is a
  single number for the whole disc.
• No X-Trans support yet; Bayer sensors only.