TASK-069: the first screen fades in under the cup instead of gliding

Until the session is known the route shown is the repository list; when it
becomes Home the change played the full-width tab glide just as the launch
cover was fading. That hand-over is now a plain fade, and the cover waits for
it (at most 1.5 s longer) before it leaves.

Agent: main (opus)

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

app/src/main/java/com/ubisam/ubgitea/MainActivity.kt

@@ -442,7 +442,11 @@ class MainActivity : ComponentActivity() {
                     // screen, so moving between code tabs or pages of one screen does not replay it.
                     val stackDepth = routeStack.size
                     val shownDepth = remember { intArrayOf(stackDepth) }
-                    SideEffect { shownDepth[0] = stackDepth }
+                    val shownReady = remember { booleanArrayOf(sessionReady) }
+                    SideEffect {
+                        shownDepth[0] = stackDepth
+                        shownReady[0] = sessionReady
+                    }
                     AnimatedContent(
                         targetState = currentRoute.takeIf { sessionReady } ?: Route.Repositories,
                         modifier = Modifier.fillMaxSize(),
@@ -450,7 +454,12 @@ class MainActivity : ComponentActivity() {
                             val fromTab = initialState.tab
                             val toTab = targetState.tab
                             val tabSwitch = stackDepth == shownDepth[0] && fromTab != null && toTab != null
-                            if (tabSwitch) {
+                            if (!shownReady[0]) {
+                                // The session has just been found: the first screen takes the
+                                // waiting one's place where it stands. Nothing was navigated, so
+                                // nothing slides.
+                                fadeIn(tween(200)).togetherWith(fadeOut(tween(90)))
+                            } else if (tabSwitch) {
                                 // Tabs sit side by side: the old one glides out as the new one
                                 // glides in, the whole width, like turning to the next page.
                                 val direction = (toTab.ordinal - fromTab.ordinal).coerceIn(-1, 1)
@@ -685,7 +694,7 @@ class MainActivity : ComponentActivity() {
                         },
                     )
                 }
-                SplashOverlay()
+                SplashOverlay(settled = sessionReady || state.sessionReadyOrNull() != null)
             }
         }
         consumeCallback(intent)

app/src/main/java/com/ubisam/ubgitea/ui/components/Motion.kt

@@ -41,8 +41,10 @@ import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clip
@@ -67,6 +69,8 @@ import com.ubisam.ubgitea.ui.theme.UBGiteaTheme
 import kotlin.math.PI
 import kotlin.math.sin
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.withTimeoutOrNull
 
 // The app's moving parts. All of them draw the launcher icon's tea cup, so the app looks like one
 // thing from the home screen inwards.
@@ -310,16 +314,23 @@ fun <S> TabGlide(
 
 const val TabGlideMillis = 320
 
+const val SplashLongestWaitMillis = 1500L
+
 private val SplashGradient = listOf(Color(0xFF4DB0FF), Color(0xFF2F98F9), Color(0xFF0A6FD8))
 
 /**
  * The launcher icon, enlarged and steaming, over the whole window for the first second after a
  * cold start. It covers the app rather than delaying it: everything underneath loads meanwhile.
+ *
+ * It leaves once [settled] says whether there is a session, so its fade does not share frames
+ * with the first screen arriving underneath, and never stays longer than [SplashLongestWaitMillis]
+ * past its own second.
  */
 @Composable
-fun SplashOverlay() {
+fun SplashOverlay(settled: Boolean) {
     var finished by rememberSaveable { mutableStateOf(false) }
     if (finished) return
+    val settledNow by rememberUpdatedState(settled)
     val alpha = remember { Animatable(1f) }
     val scale = remember { Animatable(0.85f) }
     LaunchedEffect(Unit) {
@@ -327,6 +338,11 @@ fun SplashOverlay() {
     }
     LaunchedEffect(Unit) {
         delay(1100)
+        if (!settledNow) {
+            withTimeoutOrNull(SplashLongestWaitMillis) { snapshotFlow { settledNow }.first { it } }
+            // The first screen fades in over the waiting one; let that finish under the cover.
+            delay(250)
+        }
         alpha.animateTo(0f, tween(280))
         finished = true
     }

docs/development-log.md

@@ -1615,3 +1615,17 @@ This is the append-only implementation and handoff record shared by Codex and Cl
 - Caution: published without having been seen on a device, at the product owner's decision.
   0.2.3 and older still update through the browser download; the in-app update is first used
   going from 0.2.4 to whatever comes next, so it stays unproven until then.
+
+## 2026-10-12 (continued) — TASK-069: the start no longer stutters as the cup leaves
+
+- Request: the product owner reported that at launch the cup seemed to move off towards the top
+  left as it disappeared, and that this part stuttered.
+- Cause found in the code: until the session is known the route shown is the repository list;
+  once it is known the route becomes Home. Both are tabs, so the change played the full-width tab
+  glide, at about the moment the cover was fading, on top of Home's first composition.
+- What changed: `MainActivity` gives that hand-over a plain fade and no slide. `SplashOverlay`
+  takes `settled` and, after its own 1.1 seconds, waits until the session is known (at most 1.5
+  seconds more) and for the fade underneath before it leaves.
+- Checks and results: the five required checks pass.
+- Caution: diagnosed from the code, not seen on a device. If the stutter is still there, the
+  remaining suspect is the cost of Home's first frames on that phone.

tasks/069-in-app-motion.md

@@ -22,6 +22,10 @@ The app moves where it used to jump, and what moves is the launcher icon's tea c
 9. Added after that (product owner, 2026-10-12): the tabs inside a screen glide the same way.
    전체 저장소/즐겨찾기 and 이슈/풀 리퀘스트 keep their header and tab row still while the list under
    them changes sides. The branch screen's tabs already slid (a pager) and are unchanged.
+10. Reported by the product owner (2026-10-12): the start stuttered as the cup left. The first
+    screen was gliding in sideways underneath, as if a tab had been switched, while the cover was
+    fading. The first screen now fades in where it stands, and the cover waits for it (at most
+    1.5 seconds longer) before it leaves.
 
 ## Scope
 
@@ -46,7 +50,7 @@ The app moves where it used to jump, and what moves is the launcher icon's tea c
 
 ## Acceptance criteria
 
-- [x] Each of the nine items above is in the code and the app builds.
+- [x] Each of the ten items above is in the code and the app builds.
 - [x] The splash covers the app without delaying it: sign-in, loading and the OAuth callback run
   underneath, and taps do not pass through the cover.
 - [x] Moving between code tabs, or between pages of one screen, does not replay the screen