M5: Android data layer: DAOs, Ktor client and DTOs, token store, sync engine and workers, repositories, APK updater

DAOs on M2b's Room 3 entities and KvittDatabase v1 (schema 1.json unchanged), DTOs for every wire
object and endpoint body with a round-trip test over all 80 contract examples, the Ktor client with the
section 14.3.1 headers and 14.3.2 error mapping, the Keystore-encrypted token store in auth.preferences_pb,
the sync engine of section 14.4 (push batches, pull pages, epoch recovery, rejections, clock skew, 401 and
426 handling) tested with MockEngine including AC-15.6, WorkManager triggers, every :core:model repository,
the APK updater behind an installer interface, Coil pictures, Hilt modules, Room migration test
infrastructure. Fakes: the five settled TODO(spec) comments resolved per SPEC v0.4 (settlement row in an
account's ledger carries that account's allocation).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

android/gradle/libs.versions.toml

@@ -62,6 +62,7 @@ kotlinx-coroutines-core = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-c
 kotlinx-coroutines-test = { module = "org.jetbrains.kotlinx:kotlinx-coroutines-test", version.ref = "kotlinxCoroutines" }
 kotlinx-datetime = { module = "org.jetbrains.kotlinx:kotlinx-datetime", version.ref = "kotlinxDatetime" }
 coil-compose = { module = "io.coil-kt.coil3:coil-compose", version.ref = "coil" }
+coil = { module = "io.coil-kt.coil3:coil", version.ref = "coil" }
 coil-network-ktor3 = { module = "io.coil-kt.coil3:coil-network-ktor3", version.ref = "coil" }
 vico-compose-m3 = { module = "com.patrykandpatrick.vico:compose-m3", version.ref = "vico" }
 junit = { module = "junit:junit", version.ref = "junit" }