ui: CENTER activates everything (clickable lacks DPAD_CENTER)

Compose clickable handles Enter/Space only; whether the TV's OK
(DPAD_CENTER) triggers click depends on the device's input stack -
worked on the API-36 host emulator, dead on the API-34 ATD and
possibly some TVs. A preview-tunnelled center handler now activates
drawer items, top-bar buttons, video and channel cards, and the
login/search buttons deterministically, exactly once (preview
consumption prevents the platform path from double-firing).

app/src/main/java/net/jeena/jtubetv/ui/screens/ChannelsScreen.kt

@@ -62,6 +62,7 @@ import net.jeena.jtubetv.data.api.VideoChannelDto
 import net.jeena.jtubetv.ui.list.ImagePrefetcher
 import net.jeena.jtubetv.ui.screens.list.ContainerShape
 import net.jeena.jtubetv.ui.screens.list.UnfocusedCardBg
+import net.jeena.jtubetv.ui.screens.list.dpadCenterActivatable
 
 /**
  * Channels, SmartTube-style: one row per LOCAL user.
@@ -417,6 +418,7 @@ fun ChannelCard(
         modifier = modifier
             .width(rowCardWidth())
             .padding(6.dp)
+            .dpadCenterActivatable(onClick)
             .onFocusChanged { cardFocused = it.isFocused }
             .onPreviewKeyEvent { ke ->
                 if (ke.nativeKeyEvent.action == android.view.KeyEvent.ACTION_DOWN &&

app/src/main/java/net/jeena/jtubetv/ui/screens/HomeScreen.kt

@@ -55,6 +55,7 @@ import net.jeena.jtubetv.data.api.VideoDto
 import net.jeena.jtubetv.ui.AppViewModel
 import net.jeena.jtubetv.ui.list.ListSource
 import net.jeena.jtubetv.ui.screens.list.VideoListScreen
+import net.jeena.jtubetv.ui.screens.list.dpadCenterActivatable
 
 enum class Destination(val title: String) {
     Home("Home"),
@@ -266,6 +267,7 @@ private fun TopBar(
                     else Modifier
                 )
                 .focusable()
+                .dpadCenterActivatable(onAccountClick)
                 .clickable(onClick = onAccountClick),
             verticalAlignment = Alignment.CenterVertically,
             horizontalArrangement = androidx.compose.foundation.layout.Arrangement.spacedBy(8.dp),
@@ -338,6 +340,7 @@ private fun RoundTopButton(
             )
             .then(if (focusRequester != null) Modifier.focusRequester(focusRequester) else Modifier)
             .focusable()
+            .dpadCenterActivatable(onClick)
             .clickable(onClick = onClick),
         contentAlignment = Alignment.Center,
     ) {
@@ -454,6 +457,7 @@ private fun MenuDrawerItem(
                 }
             )
             .focusable()
+            .dpadCenterActivatable(onClick)
             .clickable(onClick = onClick)
             .padding(horizontal = 24.dp, vertical = 14.dp),
         verticalAlignment = Alignment.CenterVertically,

app/src/main/java/net/jeena/jtubetv/ui/screens/SetupScreen.kt

@@ -28,6 +28,7 @@ import androidx.compose.ui.input.key.onPreviewKeyEvent
 import androidx.compose.ui.platform.LocalClipboardManager
 import androidx.compose.ui.unit.dp
 import kotlinx.coroutines.flow.StateFlow
+import net.jeena.jtubetv.ui.screens.list.dpadCenterActivatable
 
 /**
  * Feature 0: ask for instance URL + credentials once. The password is used only for
@@ -164,9 +165,6 @@ fun SetupScreen(
                 Text(message.value ?: localError.value!!, color = MaterialTheme.colorScheme.error)
             }
             Button(
-                // Deliberately always focusable: on TV a permanently disabled button
-                // is unreachable and leaves the user stuck without feedback (UX review).
-                // Validation happens on press with an inline message instead.
                 onClick = {
                     when {
                         url.value.isBlank() || username.value.isBlank() || password.value.isBlank() ->
@@ -178,7 +176,20 @@ fun SetupScreen(
                     }
                 },
                 enabled = !busy.value,
-                modifier = Modifier.fillMaxWidth(),
+                modifier = Modifier
+                    .fillMaxWidth()
+                    .dpadCenterActivatable(
+                        onClick = {
+                            when {
+                                url.value.isBlank() || username.value.isBlank() || password.value.isBlank() ->
+                                    localError.value = "All fields are required"
+                                else -> {
+                                    localError.value = null
+                                    onLogin(url.value, username.value, password.value)
+                                }
+                            }
+                        },
+                    ),
             ) {
                 if (busy.value) {
                     CircularProgressIndicator(Modifier.width(20.dp))

app/src/main/java/net/jeena/jtubetv/ui/screens/list/FocusKeys.kt

@@ -0,0 +1,24 @@
+package net.jeena.jtubetv.ui.screens.list
+
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.composed
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+
+/**
+ * Compose `clickable` handles Enter/Space but NOT the TV's DPAD_CENTER; whether
+ * CENTER works depends on each device's input translation (works on some emulators,
+ * not on others — see the API-34 ATD case). This modifier consumes CENTER *first*
+ * (preview/tunneling) so the click fires exactly once, on every device.
+ */
+fun Modifier.dpadCenterActivatable(onClick: () -> Unit): Modifier = composed {
+    onPreviewKeyEvent { ke ->
+        if (ke.nativeKeyEvent.action == android.view.KeyEvent.ACTION_DOWN &&
+            ke.nativeKeyEvent.keyCode == android.view.KeyEvent.KEYCODE_DPAD_CENTER
+        ) {
+            onClick()
+            true
+        } else false
+    }
+}

app/src/main/java/net/jeena/jtubetv/ui/screens/list/VideoCard.kt

@@ -69,6 +69,7 @@ fun VideoCard(
         onClick = onClick,
         modifier = modifier
             .padding(6.dp)
+            .dpadCenterActivatable(onClick)
             .onFocusChanged {
                 cardFocused = it.isFocused
                 if (it.isFocused) onFocused?.invoke()