UPSTREAM: manager: improve predictive back animations

This pull request introduces custom screen transition animations to
enhance the overall user experience during navigation.

The key change is the implementation of a custom slide/fade effect for
navigating from main screens (i.e., screens hosted in the bottom
navigation bar) to detail screens. Transitions between the bottom
navigation bar tabs themselves retain a simple, clean cross-fade effect
to ensure a fast and smooth user interaction.

This PR also addresses the root cause of an issue where custom
animations were being overridden by the navigation library's defaults.

During implementation, it was discovered that custom transition
animations defined in the `defaultTransitions` parameter of the
`DestinationsNavHost` in `MainActivity` were not being applied. Instead,
a default fade-in/fade-out animation was always present.

The root cause was traced to the `compose-destinations` KSP (Kotlin
Symbol Processing) code generator. By default, the generator creates a
`NavGraphSpec` (e.g., `RootNavGraph.kt`) that includes its own
`defaultTransitions` property. This property, defined at compile-time
within the generated graph object, has a higher precedence than the
`defaultTransitions` parameter supplied to the `DestinationsNavHost`
composable at runtime.

As a result, our intended custom animations were being ignored and
overridden by the generated default.

To resolve this precedence issue permanently, this PR adopts the
official configuration method recommended by the `compose-destinations`
library.

- The following KSP argument has been added to the
`app/build.gradle.kts` file:

```kotlin
ksp {
    arg("compose-destinations.defaultTransitions", "none")
}
```

- This argument instructs the code generator to omit the
`defaultTransitions` property from the generated `NavGraphSpec`.

- By removing the higher-priority, generated default, the
`defaultTransitions` parameter on `DestinationsNavHost` now functions as
the effective default, allowing our custom animation logic to execute as
intended.

The new animation logic is conditional and defined within
`MainActivity`. It distinguishes between two primary navigation types:

- Main Screen → Detail Screen:

   - Enter: The new detail screen slides in from the right.

   - Exit: The old main screen slides out to the left while fading out.

- Detail Screen → Main Screen (on Pop):

- Pop Enter: The main screen slides back in from the left while fading
in.

   - Pop Exit: The detail screen slides out to the right.

- Between Bottom Navigation Tabs:

- A simple cross-fade (`fadeIn`/`fadeOut`) is maintained for these
transitions to provide a quick and non-disruptive experience when
switching between primary sections of the app.

manager/app/build.gradle.kts

@@ -106,6 +106,10 @@ android {
     }
 }
 
+ksp {
+    arg("compose-destinations.defaultTransitions", "none")
+}
+
 dependencies {
     implementation(libs.gson)
     implementation(libs.androidx.activity.compose)

manager/app/src/main/java/com/sukisu/ultra/ui/MainActivity.kt

@@ -7,20 +7,32 @@ import android.os.Bundle
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.enableEdgeToEdge
+import androidx.compose.animation.AnimatedContentTransitionScope
+import androidx.compose.animation.EnterTransition
+import androidx.compose.animation.ExitTransition
+import androidx.compose.animation.core.tween
+import androidx.compose.animation.fadeIn
+import androidx.compose.animation.fadeOut
+import androidx.compose.animation.scaleOut
+import androidx.compose.animation.slideInHorizontally
+import androidx.compose.animation.slideOutHorizontally
 import androidx.compose.foundation.layout.*
 import androidx.compose.material3.*
 import androidx.compose.runtime.*
 import androidx.compose.ui.Modifier
 import androidx.lifecycle.lifecycleScope
+import androidx.navigation.NavBackStackEntry
 import androidx.navigation.compose.currentBackStackEntryAsState
 import androidx.navigation.compose.rememberNavController
 import com.ramcosta.composedestinations.DestinationsNavHost
+import com.ramcosta.composedestinations.animations.NavHostAnimatedDestinationStyle
 import com.ramcosta.composedestinations.generated.NavGraphs
 import com.ramcosta.composedestinations.generated.destinations.ExecuteModuleActionScreenDestination
 import com.ramcosta.composedestinations.spec.NavHostGraphSpec
 import io.sukisu.ultra.UltraToolInstall
 import com.sukisu.ultra.ksuApp
 import zako.zako.zako.zakoui.activity.util.AppData
+import com.sukisu.ultra.ui.screen.BottomBarDestination
 import com.sukisu.ultra.ui.theme.*
 import zako.zako.zako.zakoui.activity.util.*
 import zako.zako.zako.zakoui.activity.component.BottomBar
@@ -82,6 +94,10 @@ class MainActivity : ComponentActivity() {
                     val snackBarHostState = remember { SnackbarHostState() }
                     val currentDestination = navController.currentBackStackEntryAsState().value?.destination
 
+                    val bottomBarRoutes = remember {
+                        BottomBarDestination.entries.map { it.direction.route }.toSet()
+                    }
+
                     val showBottomBar = when (currentDestination?.route) {
                         ExecuteModuleActionScreenDestination.route -> false
                         else -> true
@@ -107,7 +123,47 @@ class MainActivity : ComponentActivity() {
                                 modifier = Modifier.padding(innerPadding),
                                 navGraph = NavGraphs.root as NavHostGraphSpec,
                                 navController = navController,
-                                defaultTransitions = NavigationUtils.defaultTransitions()
+                                defaultTransitions = object : NavHostAnimatedDestinationStyle() {
+                                    override val enterTransition: AnimatedContentTransitionScope<NavBackStackEntry>.() -> EnterTransition = {
+                                        // If the target is a detail page (not a bottom navigation page), slide in from the right
+                                        if (targetState.destination.route !in bottomBarRoutes) {
+                                            slideInHorizontally(initialOffsetX = { it })
+                                        } else {
+                                            // Otherwise (switching between bottom navigation pages), use fade in
+                                            fadeIn(animationSpec = tween(340))
+                                        }
+                                    }
+
+                                    override val exitTransition: AnimatedContentTransitionScope<NavBackStackEntry>.() -> ExitTransition = {
+                                        // If navigating from the home page (bottom navigation page) to a detail page, slide out to the left
+                                        if (initialState.destination.route in bottomBarRoutes && targetState.destination.route !in bottomBarRoutes) {
+                                            slideOutHorizontally(targetOffsetX = { -it / 4 }) + fadeOut()
+                                        } else {
+                                            // Otherwise (switching between bottom navigation pages), use fade out
+                                            fadeOut(animationSpec = tween(340))
+                                        }
+                                    }
+
+                                    override val popEnterTransition: AnimatedContentTransitionScope<NavBackStackEntry>.() -> EnterTransition = {
+                                        // If returning to the home page (bottom navigation page), slide in from the left
+                                        if (targetState.destination.route in bottomBarRoutes) {
+                                            slideInHorizontally(initialOffsetX = { -it / 4 }) + fadeIn()
+                                        } else {
+                                            // Otherwise (e.g., returning between multiple detail pages), use default fade in
+                                            fadeIn(animationSpec = tween(340))
+                                        }
+                                    }
+
+                                    override val popExitTransition: AnimatedContentTransitionScope<NavBackStackEntry>.() -> ExitTransition = {
+                                        // If returning from a detail page (not a bottom navigation page), scale down and fade out
+                                        if (initialState.destination.route !in bottomBarRoutes) {
+                                            scaleOut(targetScale = 0.9f) + fadeOut()
+                                        } else {
+                                            // Otherwise, use default fade out
+                                            fadeOut(animationSpec = tween(340))
+                                        }
+                                    }
+                                }
                             )
                         }
                     }