Minimal TWA launcher, built without Gradle from a Chromium checkout:

  javac  (JDK from third_party/jdk) against android.jar + androidx.browser and deps
  d8     --release --min-api 26
  aapt2  link (manifest only, no resources)
  zipalign + apksigner (self-signed key)

Signing certificate SHA-256:
  F4:D3:D0:20:67:D2:83:36:11:25:29:73:52:5B:BB:DB:C1:3B:5C:33:E1:CD:EB:BC:E8:44:8F:2A:3F:E6:5E:49

Digital Asset Links for verification are published at
  https://static.januschka.com/.well-known/assetlinks.json
so the TWA opens https://static.januschka.com/... fully verified (no CCT toolbar).