The Android build recipe lived at /tmp/build_pad.sh and depended on
/tmp/apktool.jar; /tmp gets wiped between sessions (both were lost once
mid-project and had to be rebuilt). Move the recipe into the repo as
scripts/build_emu.sh:
- checks prerequisites (java, gogio, apksigner, adb, debug keystore) with
actionable error messages
- auto-downloads apktool v3.0.3 to the stable ~/android-sdk/tools/ if
missing (never /tmp)
- uses a mktemp work dir cleaned via trap; no /tmp clutter
- --no-install flag; verifies an adb device is present before installing
- verifies the permission injection actually took effect
Tested end-to-end (build + install + app relaunch) and idempotent on
re-run. doc/README.md and development_plan.md now point here.
