build(android): make release buildable and instrumented testing possible

Four gaps that made "ship it" and "test it on hardware" impossible.

RELEASE SIGNING. assembleRelease was silently producing
app-release-unsigned.apk because there was no signingConfigs block at all —
the failure mode where you only notice at install time. Credentials now
resolve from keystore.properties, then local.properties, then
WEBTERM_RELEASE_* env; nothing is created or committed, and
keystore.properties.example is the template.

The degradation is ENFORCED, not documented. The signingConfig is only
created when credentials actually resolve — an empty config is precisely what
makes AGP emit an unsigned artifact quietly — and a guard on packageRelease
throws with an actionable message, distinguishing "not configured" from
"credentials found but the keystore file is missing: <path>". It hooks the
PACKAGE task on purpose: R8 has already run and reported by then, so a
developer without a keystore still gets the full shrink result rather than an
early abort. Verified: minifyReleaseWithR8 completes, packageRelease fails
loudly, and no unsigned APK is written.

VERSIONING. Was still the scaffold 1 / "0.1.0". Now 1 / "0.1.0-alpha01",
where the suffix is a factual claim about device verification rather than
decoration: alpha means device QA is essentially unstarted, beta means the
A34/A35 checklist blocks pass on hardware, and plain 0.1.0 means the whole
checklist is ticked. versionCode stays 1 because no artifact has ever left
the build machine.

MINIFICATION. release had isMinifyEnabled = false and an empty rules file —
so nothing had ever exercised R8 on this app, and the first release build
would have been the experiment. Now minify + resource shrinking, with a
deliberately short rules file: the actual artifacts were checked, and
kotlinx.serialization, Tink, Hilt, FCM, OkHttp, Compose and CameraX all ship
their own consumer rules, so none are re-declared. The termux packages are
kept whole because the JitPack artifacts ship no rules and :terminal-view
binds to non-API internals — it writes the public TerminalView.mEmulator
field and calls TerminalRenderer.getFontWidth()/getFontLineSpacing(). Getting
that wrong yields a build that crashes only in production.
lintVitalRelease also passes now, the two pre-existing lint ERRORS having
been fixed earlier this session.

ANDROID TEST ENABLEMENT. :app had no androidTest source set and no
instrumentation runner, which is the mechanical reason A34/A35 have no code
at all. The runner (Hilt-aware) and dependencies are wired, and a
:macrobenchmark module exists. The tests themselves are a separate change.

Verified: ./gradlew test :app:assembleDebug :app:assembleDebugAndroidTest
:app:assembleBenchmark :macrobenchmark:assembleBenchmark
:app:lintVitalRelease koverVerify -> BUILD SUCCESSFUL; 901 JVM tests, 0
failures on a forced re-execution with test-results deleted and
--no-build-cache.

android/gradle/libs.versions.toml

@@ -1,5 +1,6 @@
 ## Version catalog — single source of truth for plugin & dependency versions.
-## Pure JVM modules only (this env has NO Android SDK). See android/README.md.
+## Covers BOTH the pure Kotlin/JVM modules and the Android-framework modules (the
+## SDK is installed on this machine — see android/README.md "Android SDK setup").
 ## Kotlin pinned to 2.3.21 to match the Kotlin embedded in Gradle 9.6.1 (best
 ## compatibility with the Kotlin Gradle Plugin on Gradle 9.6).
 
@@ -52,10 +53,18 @@ datastore = "1.1.1"
 # listenablefuture conflict dep is unnecessary here).
 termux = "v0.118.0"
 # androidx-test — lets androidTest (instrumented) sources COMPILE here; they only
-# RUN on a device (no emulator installed → deferred to device QA, plan §7).
+# RUN on a device/emulator (plan §7 — the A34 E2E suite needs a real `npm start` host).
 androidxTestExtJunit = "1.2.1"
 androidxTestCore = "1.6.1"
 androidxTestRunner = "1.6.2"
+androidxTestRules = "1.6.1"
+# Espresso + UiAutomator drive the A35 happy path (in-process Compose assertions and
+# out-of-process device interaction respectively). Pinned to the androidx-test 1.6 line.
+espresso = "3.6.1"
+uiautomator = "2.3.0"
+# Macrobenchmark (A35) — startup/frame timing measured from a SEPARATE `com.android.test`
+# module against a non-debuggable, minified `benchmark` variant of :app.
+benchmark = "1.3.4"
 # QR pairing (A19): CameraX preview/analysis + on-device ML Kit barcode scanning.
 camerax = "1.4.1"
 mlkitBarcode = "17.3.0"
@@ -127,6 +136,20 @@ termux-terminal-emulator = { module = "com.github.termux.termux-app:terminal-emu
 androidx-test-ext-junit = { module = "androidx.test.ext:junit", version.ref = "androidxTestExtJunit" }
 androidx-test-core = { module = "androidx.test:core", version.ref = "androidxTestCore" }
 androidx-test-runner = { module = "androidx.test:runner", version.ref = "androidxTestRunner" }
+androidx-test-rules = { module = "androidx.test:rules", version.ref = "androidxTestRules" }
+androidx-test-espresso-core = { module = "androidx.test.espresso:espresso-core", version.ref = "espresso" }
+androidx-test-uiautomator = { module = "androidx.test.uiautomator:uiautomator", version.ref = "uiautomator" }
+# Compose UI test — BOM-managed (do NOT pin). `ui-test-manifest` is a debugImplementation:
+# it supplies the empty activity `createComposeRule()` launches into.
+androidx-compose-ui-test-junit4 = { module = "androidx.compose.ui:ui-test-junit4" }
+androidx-compose-ui-test-manifest = { module = "androidx.compose.ui:ui-test-manifest" }
+# Hilt instrumented testing — supplies `HiltAndroidRule` + the generated
+# `dagger.hilt.android.testing.HiltTestApplication` that :app's custom runner installs.
+# REQUIRES kspAndroidTest(hilt-compiler); without the processor HiltTestApplication is
+# never generated and the runner will not compile.
+hilt-android-testing = { module = "com.google.dagger:hilt-android-testing", version.ref = "hilt" }
+# Macrobenchmark (A35) — used by the :macrobenchmark `com.android.test` module only.
+androidx-benchmark-macro-junit4 = { module = "androidx.benchmark:benchmark-macro-junit4", version.ref = "benchmark" }
 
 # QR pairing camera (A19)
 androidx-camera-core = { module = "androidx.camera:camera-core", version.ref = "camerax" }
@@ -148,6 +171,17 @@ unit-test = ["junit-jupiter", "kotlinx-coroutines-test", "turbine", "mockk"]
 # CameraX (A19 QR pairing) — preview + analysis + PreviewView.
 camerax = ["androidx-camera-core", "androidx-camera-camera2", "androidx-camera-lifecycle", "androidx-camera-view"]
 
+# Instrumented (androidTest) foundation — wired into :app's androidTestImplementation.
+# JUnit4 arrives transitively via androidx.test.ext:junit (AndroidJUnitRunner is JUnit4-only;
+# the JVM unit tests stay on the JUnit5 platform, which instrumented tasks never touch).
+android-instrumented-test = [
+    "androidx-test-ext-junit",
+    "androidx-test-core",
+    "androidx-test-runner",
+    "androidx-test-rules",
+    "androidx-test-espresso-core",
+]
+
 # Compose UI + Material 3 (+ Adaptive) — wired into :app implementation. All
 # BOM-managed; add ui-tooling separately as a debugImplementation.
 compose = [
@@ -167,6 +201,12 @@ kotlin-jvm = { id = "org.jetbrains.kotlin.jvm", version.ref = "kotlin" }
 kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
 android-library = { id = "com.android.library", version.ref = "agp" }
 android-application = { id = "com.android.application", version.ref = "agp" }
+# NOTE: there is deliberately NO `android-test` alias for :macrobenchmark's
+# `com.android.test` plugin. The two aliases above put AGP on the build classpath with
+# an "unknown version", so a THIRD versioned alias for the same artifact is rejected
+# ("plugin is already on the classpath with an unknown version"). :macrobenchmark
+# therefore applies `id("com.android.test")` bare and inherits the `agp` version above —
+# exactly the pattern :terminal-view uses for `id("com.android.library")`.
 kover = { id = "org.jetbrains.kotlinx.kover", version.ref = "kover" }
 # NOTE: AGP 9+ has BUILT-IN Kotlin support — Android modules apply only the
 # android plugin, NOT a separate org.jetbrains.kotlin.android (it errors out).