The phone client is Tauri v2 mobile (operator decision), so it reuses the Vue frontend and the Rust store and sync engine that already exist rather than becoming a third implementation to keep in step by hand. gen/android is committed. tauri android init generated it, its own .gitignore already excludes the build outputs and every keystore file, and CI must not have to regenerate a project that manifest edits will accumulate in. What the scaffold confirms is that the image's JDK pin was load-bearing rather than incidental: Tauri templated Gradle 8.14.3 with AGP 8.11.0, and CI-android's versions.env records that JDK 25 needs Gradle 9.1.0+ and that anything older fails with an opaque "25.0.3" message. Picking 17 for ci-tauri-android avoided exactly that. namespace and applicationId came out as com.fabledsword.thoughtsync, matching the desktop identifier, so the app-data story stays consistent. The lane builds a DEBUG APK for arm64 only. Release APKs need signing, and the keystore has to be generated by the operator and never pass through CI logs or an agent session — the constraint recorded for the updater key applies unchanged. Gradle's throwaway debug keystore needs nothing from anyone, so this can prove the app compiles and packages today and grow a signed job when a key exists. arm64 is every real device; the image carries the other three ABIs, so widening is a word. Triggered by frontend/** as well as desktop/**, because generate_context! compiles the frontend into the app — the same reasoning that widened desktop.yml. Android, desktop and web are peers on one quality bar, and a frontend commit that skipped this lane would ship a stale phone build. Green here will mean it BUILT. A Linux runner cannot execute an APK, so nothing in this lane proves the app runs, renders, or is usable by finger. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>