feat: add expand, queue chip, and account switcher animations

- F4: AnimatedContent with expand/shrink transitions on "Show more" text
- F6: Pulsing alpha animation on queue chip when status is UPLOADING
- F10: Staggered slideInHorizontally + fadeIn entrance for account switcher items

app/src/main/java/com/swoosh/microblog/ui/feed/FeedScreen.kt

@@ -7,6 +7,7 @@ import android.content.Intent
 import androidx.compose.animation.AnimatedContent
 import androidx.compose.animation.AnimatedVisibility
 import androidx.compose.animation.animateColorAsState
+import androidx.compose.animation.core.animateFloat
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.infiniteRepeatable
 import androidx.compose.animation.core.rememberInfiniteTransition
@@ -1124,7 +1125,19 @@ fun AccountSwitcherBottomSheet(
                 modifier = Modifier.padding(horizontal = 24.dp, vertical = 8.dp)
             )
 
-            accounts.forEach { account ->
+            accounts.forEachIndexed { index, account ->
+                var itemVisible by remember { mutableStateOf(false) }
+                LaunchedEffect(Unit) {
+                    delay(SwooshMotion.StaggerDelayMs * index)
+                    itemVisible = true
+                }
+                AnimatedVisibility(
+                    visible = itemVisible,
+                    enter = slideInHorizontally(
+                        initialOffsetX = { -it / 4 },
+                        animationSpec = SwooshMotion.gentle()
+                    ) + fadeIn(SwooshMotion.quick())
+                ) {
                     AccountListItem(
                         account = account,
                         isActive = account.id == activeAccountId,
@@ -1133,6 +1146,7 @@ fun AccountSwitcherBottomSheet(
                         onRename = { onRenameAccount(account) }
                     )
                 }
+            }
 
             if (accounts.size < 5) {
                 HorizontalDivider(modifier = Modifier.padding(horizontal = 16.dp, vertical = 8.dp))
@@ -1475,25 +1489,32 @@ fun PostCardContent(
                     maxLines = if (expanded) Int.MAX_VALUE else 8
                 )
             } else {
+                AnimatedContent(
+                    targetState = expanded,
+                    transitionSpec = {
+                        (fadeIn(SwooshMotion.quick()) + expandVertically(animationSpec = SwooshMotion.snappy()))
+                            .togetherWith(fadeOut(SwooshMotion.quick()) + shrinkVertically(animationSpec = SwooshMotion.snappy()))
+                    },
+                    label = "expandText"
+                ) { isExpanded ->
+                    Column {
                         Text(
-                    text = displayText,
+                            text = if (isExpanded || post.textContent.length <= 280) post.textContent
-                    style = MaterialTheme.typography.bodyLarge,
+                                   else post.textContent.take(280) + "...",
-                    color = MaterialTheme.colorScheme.onSurface,
+                            style = MaterialTheme.typography.bodyMedium,
-                    maxLines = if (expanded) Int.MAX_VALUE else 8,
+                            maxLines = if (isExpanded) Int.MAX_VALUE else 8,
                             overflow = TextOverflow.Ellipsis
                         )
+                        if (!isExpanded && post.textContent.length > 280) {
+                            TextButton(
+                                onClick = { expanded = true },
+                                contentPadding = PaddingValues(0.dp)
+                            ) {
+                                Text("Show more", style = MaterialTheme.typography.labelMedium)
+                            }
+                        }
+                    }
                 }
-
-            if (!expanded && post.textContent.length > 280) {
-                Spacer(modifier = Modifier.height(4.dp))
-                Text(
-                    text = "Show more",
-                    style = MaterialTheme.typography.labelMedium.copy(fontWeight = FontWeight.Bold),
-                    color = MaterialTheme.colorScheme.primary,
-                    modifier = Modifier
-                        .clickable { expanded = true }
-                        .padding(vertical = 2.dp)
-                )
             }
 
             // Image grid
@@ -1595,10 +1616,22 @@ fun PostCardContent(
                     QueueStatus.FAILED -> "Upload failed"
                     else -> ""
                 }
+                val isUploading = post.queueStatus == QueueStatus.UPLOADING
+                val infiniteTransition = rememberInfiniteTransition(label = "queuePulse")
+                val chipAlpha by infiniteTransition.animateFloat(
+                    initialValue = if (isUploading) 0.6f else 1f,
+                    targetValue = 1f,
+                    animationSpec = infiniteRepeatable(
+                        animation = tween(600),
+                        repeatMode = RepeatMode.Reverse
+                    ),
+                    label = "uploadPulse"
+                )
                 Row(verticalAlignment = Alignment.CenterVertically) {
                     AssistChip(
                         onClick = {},
-                        label = { Text(queueLabel, style = MaterialTheme.typography.labelSmall) }
+                        label = { Text(queueLabel, style = MaterialTheme.typography.labelSmall) },
+                        modifier = Modifier.graphicsLayer { alpha = if (isUploading) chipAlpha else 1f }
                     )
                     if (post.queueStatus == QueueStatus.QUEUED_PUBLISH || post.queueStatus == QueueStatus.QUEUED_SCHEDULED) {
                         Spacer(modifier = Modifier.width(8.dp))