fix: keep the check code on the Done screen; make release APKs reproducible on F-Droid

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## Unreleased
+
+- The check code stays on screen once enrolment finishes, labelled and with a reminder that it
+  should match the board and Sapwood, instead of disappearing as soon as the board's answer is
+  confirmed. It clears when the owner leaves the screen.
+- Release builds no longer embed git metadata, so the APK built by F-Droid matches the one
+  published here whatever checkout it was built from.
+
 ## 0.7.0 (2026-09-26)
 
 - Adding a phone now scans Sapwood's own invite QR instead of the other way round: "Add a phone"

app/build.gradle.kts

@@ -49,6 +49,10 @@ android {
     buildTypes {
         release {
             isMinifyEnabled = false
+            // Keep git metadata out of the APK: a build from a worktree or a tarball records
+            // NO_VALID_GIT_FOUND where F-Droid's clone records the commit, and that one file was
+            // enough to fail F-Droid's reproducible-build check for 0.5.0.
+            vcsInfo.include = false
             proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
             if (releaseSigning.getProperty("storeFile") != null) {
                 signingConfig = signingConfigs.getByName("release")

app/src/main/kotlin/dev/forgesworn/cambium/unlock/UnlockEnrolActivity.kt

@@ -285,7 +285,7 @@ class UnlockEnrolActivity : AppCompatActivity() {
                 conflicted = true
                 binding.enrolBatteryButton.isVisible = false
                 binding.enrolStatus.text = getString(R.string.enrol_conflict_after, storedId, handOff.id)
-                binding.enrolCheckCode.isVisible = false
+                showCheckCode(false)
             }
             handOff.wipe()
             return
@@ -300,7 +300,7 @@ class UnlockEnrolActivity : AppCompatActivity() {
                 enrolSecretHex = null
                 binding.enrolConfirmButton.isVisible = false
                 binding.enrolStatus.text = getString(R.string.enrol_conflict, first.id, handOff.id)
-                binding.enrolCheckCode.isVisible = false
+                showCheckCode(false)
             }
             handOff.wipe()
             return
@@ -319,7 +319,7 @@ class UnlockEnrolActivity : AppCompatActivity() {
         binding.enrolRetryButton.isVisible = false
         binding.enrolStatus.text = getString(R.string.enrol_received)
         binding.enrolCheckCode.text = checkCode(envelope.ephemeralPubkeyHex).orEmpty()
-        binding.enrolCheckCode.isVisible = true
+        showCheckCode(true)
         binding.enrolConfirmButton.isVisible = true
         lifecycleScope.launch {
             delay(PENDING_TIMEOUT_MILLIS)
@@ -330,7 +330,7 @@ class UnlockEnrolActivity : AppCompatActivity() {
                 enrolSecretHex = null
                 binding.enrolConfirmButton.isVisible = false
                 binding.enrolStatus.text = getString(R.string.enrol_timed_out, handOff.id)
-                binding.enrolCheckCode.isVisible = false
+                showCheckCode(false)
             }
         }
         promptSeal()
@@ -393,8 +393,9 @@ class UnlockEnrolActivity : AppCompatActivity() {
         PairingStore(this).setKeepAliveEnabled(true)
         HeartwoodKeepAliveService.start(this)
 
+        // Left showing on Done: the owner may still be comparing it with Sapwood or the board's
+        // own card at this point, and it stays harmless to see once the slot secret is sealed.
         binding.enrolConfirmButton.isVisible = false
-        binding.enrolCheckCode.isVisible = false
         binding.enrolStatus.text = getString(R.string.enrol_done, handOff.id)
         binding.enrolBatteryButton.isVisible = !isIgnoringBatteryOptimisations(this)
         binding.enrolDoneButton.setText(R.string.enrol_finished)
@@ -412,6 +413,13 @@ class UnlockEnrolActivity : AppCompatActivity() {
     private fun shortLabel(pairing: Pairing): String =
         pairing.label?.takeIf { it.isNotBlank() } ?: pairing.displayLabel().let { if (it.length > 20) it.take(12) + "…" else it }
 
+    /** The check code and its label/hint always show or hide together. */
+    private fun showCheckCode(visible: Boolean) {
+        binding.enrolCheckCodeLabel.isVisible = visible
+        binding.enrolCheckCode.isVisible = visible
+        binding.enrolCheckCodeHint.isVisible = visible
+    }
+
     private fun showOnly(message: String) {
         binding.enrolBody.isVisible = false
         binding.enrolScanButton.isVisible = false

app/src/main/res/layout/activity_unlock_enrol.xml

@@ -140,12 +140,24 @@
             android:textColor="@color/on_background"
             tools:text="Waiting for the board…" />
 
+        <TextView
+            android:id="@+id/enrolCheckCodeLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:layout_marginTop="16dp"
+            android:fontFamily="monospace"
+            android:gravity="center"
+            android:text="@string/enrol_check_code_label"
+            android:textColor="@color/on_background_muted"
+            android:visibility="gone"
+            tools:visibility="visible" />
+
         <TextView
             android:id="@+id/enrolCheckCode"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_gravity="center_horizontal"
-            android:layout_marginTop="16dp"
             android:fontFamily="monospace"
             android:letterSpacing="0.2"
             android:textColor="@color/accent"
@@ -155,6 +167,18 @@
             tools:text="8131"
             tools:visibility="visible" />
 
+        <TextView
+            android:id="@+id/enrolCheckCodeHint"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:fontFamily="monospace"
+            android:gravity="center"
+            android:text="@string/enrol_check_code_hint"
+            android:textColor="@color/on_background_muted"
+            android:visibility="gone"
+            tools:visibility="visible" />
+
         <Button
             android:id="@+id/enrolConfirmButton"
             android:layout_width="wrap_content"

app/src/main/res/values/strings.xml

@@ -157,6 +157,8 @@
     <string name="enrol_retry">Retry</string>
     <string name="enrol_waiting">Waiting for the board… If it says it added this phone but nothing arrives here, revoke the id it shows in Sapwood.</string>
     <string name="enrol_received">The board added this phone. Check that the board shows the same six characters, then confirm with your phone\'s screen lock to keep the unlock key on this phone.</string>
+    <string name="enrol_check_code_label">Check code</string>
+    <string name="enrol_check_code_hint">It should match the check code on the board and in Sapwood.</string>
     <string name="enrol_confirm">Confirm</string>
     <string name="enrol_prompt_title">Keep the unlock key on this phone</string>
     <string name="enrol_not_confirmed">Not confirmed yet. Confirm to finish; if you leave now, revoke record %1$d on the board in Sapwood.</string>