feat(bubble): drag-to-dismiss zone, no auto-timeout, dismiss on conversation enter

- MessageBubbleOverlay: drag-to-dismiss target at bottom-center, no 12s auto-timeout (persists until read)
- MessageBubbleController: dismissFor clears bubble when its conversation is opened
- ActiveThreadMonitor: calls dismissFor on enter, clearing the bubble for that thread

app/src/main/java/app/closer/notifications/ActiveThreadMonitor.kt

@@ -12,13 +12,19 @@ import javax.inject.Singleton
  * notification and this monitor isn't consulted — which is the desired behaviour.
  */
 @Singleton
-class ActiveThreadMonitor @Inject constructor() {
+class ActiveThreadMonitor @Inject constructor(
+    private val messageBubbleController: MessageBubbleController
+) {
     @Volatile
     var activeQuestionId: String? = null
         private set
 
     fun enter(questionId: String) {
-        if (questionId.isNotBlank()) activeQuestionId = questionId
+        if (questionId.isNotBlank()) {
+            activeQuestionId = questionId
+            // Opening the conversation counts as reading it — clear any chat bubble for it.
+            messageBubbleController.dismissFor(questionId)
+        }
     }
 
     fun leave(questionId: String) {

app/src/main/java/app/closer/notifications/MessageBubbleController.kt

@@ -40,4 +40,9 @@ class MessageBubbleController @Inject constructor() {
     fun dismiss() {
         _bubble.value = null
     }
+
+    /** Clear the bubble once its conversation is opened (the message has been read). */
+    fun dismissFor(questionId: String) {
+        _bubble.update { current -> if (current?.questionId == questionId) null else current }
+    }
 }

app/src/main/java/app/closer/ui/components/MessageBubbleOverlay.kt

@@ -13,14 +13,15 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.Chat
+import androidx.compose.material.icons.filled.Close
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableFloatStateOf
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
@@ -40,7 +41,6 @@ import app.closer.notifications.MessageBubbleController
 import app.closer.ui.theme.CloserPalette
 import coil.compose.AsyncImage
 import dagger.hilt.android.lifecycle.HiltViewModel
-import kotlinx.coroutines.delay
 import javax.inject.Inject
 import kotlin.math.roundToInt
 
@@ -80,10 +80,33 @@ fun MessageBubbleOverlay(
         var offsetX by remember(current.questionId) { mutableFloatStateOf(rightEdge) }
         var offsetY by remember(current.questionId) { mutableFloatStateOf(maxYpx * 0.32f) }
 
-        // Auto-dismiss if the user neither opens nor moves it for a while.
-        LaunchedEffect(current.questionId, current.count) {
-            delay(12_000)
-            viewModel.dismiss()
+        // The bubble persists until the message is read — opening the conversation clears it (via
+        // ActiveThreadMonitor) — or the user flicks it down onto the dismiss target. No timeout.
+        var dragging by remember(current.questionId) { mutableStateOf(false) }
+        var nearDismiss by remember(current.questionId) { mutableStateOf(false) }
+        val dismissZonePx = with(density) { 150.dp.toPx() }
+
+        // Drag-to-dismiss target at the bottom-center, shown only while dragging.
+        if (dragging) {
+            Box(
+                modifier = Modifier
+                    .align(Alignment.BottomCenter)
+                    .padding(bottom = 48.dp)
+                    .size(if (nearDismiss) 66.dp else 54.dp)
+                    .shadow(6.dp, CircleShape)
+                    .clip(CircleShape)
+                    .background(
+                        if (nearDismiss) CloserPalette.PinkAccentDeep else Color.Black.copy(alpha = 0.45f)
+                    ),
+                contentAlignment = Alignment.Center
+            ) {
+                Icon(
+                    imageVector = Icons.Filled.Close,
+                    contentDescription = "Dismiss",
+                    tint = Color.White,
+                    modifier = Modifier.size(28.dp)
+                )
+            }
         }
 
         Box(
@@ -96,14 +119,26 @@ fun MessageBubbleOverlay(
                 .border(2.5.dp, Color.White, CircleShape)
                 .pointerInput(current.questionId) {
                     detectDragGestures(
+                        onDragStart = { dragging = true },
                         onDrag = { change, drag ->
                             change.consume()
                             offsetX = (offsetX + drag.x).coerceIn(0f, rightEdge)
                             offsetY = (offsetY + drag.y).coerceIn(marginPx, maxYpx - sizePx - marginPx)
+                            nearDismiss = (offsetY + sizePx) > (maxYpx - dismissZonePx)
                         },
                         onDragEnd = {
-                            // Snap to whichever side is closer (chat-head behaviour).
-                            offsetX = if (offsetX + sizePx / 2f < maxXpx / 2f) marginPx else rightEdge
+                            dragging = false
+                            if (nearDismiss) {
+                                viewModel.dismiss()
+                            } else {
+                                // Snap to whichever side is closer (chat-head behaviour).
+                                offsetX = if (offsetX + sizePx / 2f < maxXpx / 2f) marginPx else rightEdge
+                            }
+                            nearDismiss = false
+                        },
+                        onDragCancel = {
+                            dragging = false
+                            nearDismiss = false
                         }
                     )
                 }