feat: add android-fs5 CLI toolset

- fs5 entrypoint with status, push, pull, app, shell, logs commands
- lib/adb.sh: ADB wrapper functions with idempotency and --force guards
- lib/output.sh: human + JSON output formatting via Python
- 33 bats tests (6 status, 9 transfer, 7 app, 5 shell, 6 logs) — all passing
- Zero shellcheck warnings
- .env-based config (device serial, log path)
- Spec-Driven Development artifacts in specs/001-android-fs5-management/

Device: exone GmbH FS5 (RD51QE202392, Android 9)

.gitignore

@@ -0,0 +1,3 @@
+.env
+fs5.log
+*.log