SolidCraft 0.28.0a for Android

SolidCraft 0.28.0a for Android (SolidCraft 0.28.0, port release a).

Built from upstream SolidCraft v0.28.0 (ee6b8560) with the Android port on top.

Install: download SolidCraft-0.28.0a-android-arm64.apk on an Android 8.0+ phone or tablet (arm64) and open it, allowing installs from that source; or adb install -r SolidCraft-0.28.0a-android-arm64.apk. Signed with a development key: uninstall a build from elsewhere first if Android refuses to update it.

Works: the full SolidCraft app (sketches, features, the timeline, the Render workspace) on Vulkan or GLES; mouse and keyboard as on the desktop (hover, selection, navigation buttons, wheel, right-click menu, shortcuts); touch (one finger orbits, tap selects, two fingers pan, pinch zooms, a finger drags a dialog's arrows); Back closes what is open; open, save, import and export through Android's file picker (STEP, STL, 3MF and OBJ tested); the on-screen keyboard for typing. Port-only: helical B-rep, custom and clearance threads (docs/android-threads.md) and involute gears: spur, helical, herringbone, internal, rack, bevel, miter, worm, worm wheel, crossed helical (docs/android-gears.md). The port saves designs one file format past upstream's release, so upstream's releases ask to be updated instead of opening them; export STEP to share.

Not yet: the on-screen keyboard covers the lower half of the screen (the app doesn't move above it), the phone layout is usable but cramped (best on a tablet or a foldable's inner screen), autosave recovery. Known issues, with work-arounds: docs/android-known-issues.md. How to use it: docs/android-touch.md; details: docs/android.md.