Skip current APKs during project updates

AGENTS.md

@@ -1400,6 +1400,15 @@ mutable at runtime from the phone.
   in *what* counts as stale, only in building past that answer once any
   one component tripped it. Regression test:
   `a_pull_touching_one_component_does_not_rebuild_its_sibling`.
+- **A project-wide Update installs only the APKs that are waiting on this
+  phone.** Skipping a current APK's build was only half of the rule above:
+  after the pull, `startProjectUpdate` re-read the correctly current
+  component and then downloaded and offered every APK in the project to the
+  installer anyway. This showed up on a server-only change as an APK update
+  despite the card already knowing the installed copy was current.
+  `needsInstall` is deliberately the one predicate used both to make the
+  card's Update button pressable and to select the APKs that press installs;
+  the reason a project needs attention may belong to a sibling component.
 - **Two words for one measurement is a bug even when both are true.**
   `MismatchedPairNote` said a sibling still on its old build was "older
   than this build," while `freshnessNote` already has a word for that

app/androidApp/src/main/kotlin/com/example/devupdater/UpdaterScreen.kt

@@ -1127,7 +1127,7 @@ private fun AppListScreen(
 
     /**
      * Update is the whole way from the remote to this phone: pull, build what that brought in, and
-     * install every APK it produced.
+     * install each APK whose built copy is newer than what is on this phone.
      *
      * Written as the two halves in order rather than as a route of its own, because each half is
      * already a thing this app does and reports: the pull-and-build reports in the project's row
@@ -1170,7 +1170,12 @@ private fun AppListScreen(
             // fired together means the second replaces the first on
             // screen, and a component silently not installed is worse than
             // one that says it is waiting.
-            for (component in fresh.components.filter { it.apk != null }) {
+            val installed = installedTimes[fresh.key].orEmpty()
+            val variants = chosenVariants[fresh.key].orEmpty()
+            for (component in
+                fresh.components.filter {
+                    needsInstall(it, installed[it.name], variants[it.name])
+                }) {
                 // Not the one whose build just failed: its row already
                 // says so, and asking for it again would run the same
                 // failing command a second time to say it twice.
@@ -4318,11 +4323,27 @@ private fun hasWorkWaiting(
         entry.newCommits ||
         entry.components.any { component ->
             component.isStale ||
-                component.apk?.let {
+                needsInstall(
-                    !isUpToDate(it, installedTimes[component.name], chosenVariants[component.name])
+                    component,
-                } == true
+                    installedTimes[component.name],
+                    chosenVariants[component.name],
+                )
         }
 
+/**
+ * Whether this component has an APK that would change what is installed on this phone.
+ *
+ * Shared by the card's Update button and the project-wide Update loop: once a pull has left an APK
+ * current, the button's reason for being enabled may belong to a sibling server, and that must not
+ * make this APK an install candidate anyway.
+ */
+private fun needsInstall(
+    component: ProjectComponent,
+    installedLastUpdateTimeMillis: Long?,
+    chosenVariantPath: String?,
+): Boolean =
+    component.apk?.let { !isUpToDate(it, installedLastUpdateTimeMillis, chosenVariantPath) } == true
+
 private fun isUpToDate(
     apk: ComponentApk,
     installedLastUpdateTimeMillis: Long?,