SolidCraft 0.23.0a for Android

SolidCraft 0.23.0a for Android (SolidCraft 0.23.0, port release a).

Built from upstream SolidCraft v0.23.0 (7770f898) with the Android port on top.

Install: download SolidCraft-0.23.0a-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-0.23.0a-android-arm64.apk. Signed with a development key: uninstall a build from elsewhere first if Android refuses to update it.

New in this release: SolidCraft 0.23.0 (upstream's notes: solid section views, drawn cosmetic threads, text parameters, sheet-metal Perforate, new themes and translations). Port-only: the Gear command (Create › Gear) with ten involute gear types, live preview, bore, keyway and hub, and Edit Gear (docs/android-gears.md); OK runs long features off the window thread (no "not responding" dialog); the system bars are hidden so a tablet's taskbar doesn't cover the app. Fixed: Save As names the tab after the name typed in the picker (it showed "Untitled (4)"). Tested on a Pixel 9, a Galaxy Tab and the Pixel Tablet emulator.

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. How to use it: docs/android-touch.md; details: docs/android.md.