feat(#553): animate reaction WS event (ily / <3 / good bot → hearts)

app/src/main/java/com/m57/hermescontrol/data/ws/EventParser.kt

@@ -126,6 +126,11 @@ object EventParser {
                 WsEvent.SessionUpdated(payload)
             }
 
+            "reaction" -> {
+                val kind = payload?.get("kind") as? String ?: ""
+                WsEvent.ReactionEvent(kind)
+            }
+
             "approval.request" -> {
                 val command = payload?.get("command") as? String
                 val description = payload?.get("description") as? String

app/src/main/java/com/m57/hermescontrol/data/ws/WsEvent.kt

@@ -152,6 +152,17 @@ sealed class WsEvent {
         val data: Map<String, Any?>?,
     ) : WsEvent()
 
+    // ── Reaction event ────────────────────────────────────────────────────
+
+    /**
+     * Backend emitted an affection reaction (ily / <3 / good bot).
+     * Payload: `{ "kind": "<str>" }`. Purely cosmetic — play a hearts
+     * animation in the chat UI; no persistence needed.
+     */
+    data class ReactionEvent(
+        val kind: String = "",
+    ) : WsEvent()
+
     // ── Fallback ─────────────────────────────────────────────────────────
 
     data class Unknown(

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatScreen.kt

@@ -33,6 +33,7 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.imePadding
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
@@ -86,6 +87,7 @@ import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.SideEffect
 import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -108,6 +110,7 @@ import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.KeyboardType
 import androidx.compose.ui.text.input.PasswordVisualTransformation
 import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import androidx.core.content.ContextCompat
@@ -411,6 +414,14 @@ fun ChatScreen(
                     streamingMessage = streamingState.streamingMessage,
                     isThinking = streamingState.isThinking,
                 )
+
+                // Reaction hearts animation (purely cosmetic — fades out
+                // automatically after the ViewModel clears the state)
+                key(state.reactionTriggerId) {
+                    ReactionHeartsOverlay(
+                        reactionKind = state.reactionKind,
+                    )
+                }
             }
 
             ChatInputBar(
@@ -1955,3 +1966,89 @@ private fun ReloginDialog(
         },
     )
 }
+
+// ── Reaction hearts animation ──────────────────────────────────────────
+
+/**
+ * Lightweight floating-hearts animation triggered by a `reaction` WS event.
+ * Hearts rise from the bottom-center of the chat area, drift slightly
+ * horizontally, and fade out — purely cosmetic, no persistence.
+ */
+@Composable
+private fun ReactionHeartsOverlay(
+    reactionKind: String?,
+    modifier: Modifier = Modifier,
+) {
+    val emojis =
+        remember(reactionKind) {
+            when (reactionKind) {
+                "ily", "<3", "good bot" ->
+                    listOf("💗", "❤️", "💕", "💖", "🩷", "💘", "💝")
+                else -> listOf("💗", "❤️", "💕", "💖")
+            }
+        }
+
+    androidx.compose.animation.AnimatedVisibility(
+        visible = reactionKind != null,
+        enter = fadeIn(animationSpec = tween(200)),
+        exit = fadeOut(animationSpec = tween(400)),
+        modifier = modifier.fillMaxSize(),
+    ) {
+        Box(
+            modifier = Modifier.fillMaxSize(),
+            contentAlignment = Alignment.BottomCenter,
+        ) {
+            emojis.forEachIndexed { index, emoji ->
+                key("heart_$index") {
+                    FloatingHeart(
+                        emoji = emoji,
+                        delayMs = index * 120L + 100L,
+                        horizontalOffset = ((index - emojis.size / 2) * 28).dp,
+                    )
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun FloatingHeart(
+    emoji: String,
+    delayMs: Long,
+    horizontalOffset: Dp,
+) {
+    val alpha = remember { Animatable(0f) }
+    val offsetY = remember { Animatable(0f) }
+
+    LaunchedEffect(Unit) {
+        delay(delayMs)
+        // Phase 1: fade in quickly at the bottom
+        launch {
+            alpha.animateTo(
+                targetValue = 1f,
+                animationSpec = tween(durationMillis = 200, easing = FastOutSlowInEasing),
+            )
+            // Phase 2: fade out slowly while rising
+            alpha.animateTo(
+                targetValue = 0f,
+                animationSpec = tween(durationMillis = 1400, easing = LinearEasing),
+            )
+        }
+        // Float upward over the full animation
+        launch {
+            offsetY.animateTo(
+                targetValue = -220f,
+                animationSpec = tween(durationMillis = 1600, easing = LinearEasing),
+            )
+        }
+    }
+
+    Text(
+        text = emoji,
+        fontSize = 24.sp,
+        modifier =
+            Modifier
+                .offset(x = horizontalOffset, y = offsetY.value.dp)
+                .graphicsLayer(alpha = alpha.value),
+    )
+}

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatViewModel.kt

@@ -76,6 +76,10 @@ data class ChatUiState(
     val commandCatalog: CommandCatalog = CommandCatalog(),
     // Attachment state
     val pendingAttachments: List<Attachment> = emptyList(),
+    // Reaction animation — set when a reaction WS event arrives, auto-clears
+    val reactionKind: String? = null,
+    /** Monotonic trigger ID so consecutive same-kind reactions re-animate. */
+    val reactionTriggerId: Long = 0L,
 ) {
     /** Convenience — derived from [connectionStatus]. */
     val isConnected: Boolean get() = connectionStatus == ConnectionStatus.CONNECTED
@@ -108,7 +112,7 @@ data class SecretPromptUi(
 class ChatViewModel(
     application: Application,
     private val startCleanup: Boolean,
-    private val repo: ChatPersistenceRepository =
+    repo: ChatPersistenceRepository =
         ChatPersistenceRepository(
             HermesDatabase.get(application).chatMessageDao(),
         ),
@@ -121,8 +125,13 @@ class ChatViewModel(
     private val _streamingState = MutableStateFlow(StreamingState())
     val streamingState: StateFlow<StreamingState> = _streamingState.asStateFlow()
 
+    /** Tracks the auto-clear coroutine for reaction animations. */
+    private var reactionClearJob: Job? = null
+
     private val wsClient = HermesWsClient
 
+    // ── Session persistence ──────────────────────────────────────────────
+    private val repo: ChatPersistenceRepository = repo
     private val slashDispatcher = SlashCommandDispatcher()
     private val searchDelegate =
         ChatSearchDelegate(
@@ -379,6 +388,23 @@ class ChatViewModel(
                 // it via a LaunchedEffect and triggers the snackbar.
             }
 
+            is WsEvent.ReactionEvent -> {
+                // Cancel any previous auto-clear to avoid race (agy finding #1)
+                reactionClearJob?.cancel()
+                _uiState.update {
+                    it.copy(
+                        reactionKind = event.kind,
+                        reactionTriggerId = it.reactionTriggerId + 1L,
+                    )
+                }
+                // Auto-clear after the animation duration
+                reactionClearJob =
+                    viewModelScope.launch {
+                        delay(2_000L)
+                        _uiState.update { it.copy(reactionKind = null) }
+                    }
+            }
+
             else -> { /* reducer handles these */ }
         }
     }

app/src/main/java/com/m57/hermescontrol/ui/chat/ChatWsEventReducer.kt

@@ -94,6 +94,9 @@ object ChatWsEventReducer {
             is WsEvent.SudoRequest -> ReducerResult(state = state, streamingState = streamingState)
 
             is WsEvent.SecretRequest -> ReducerResult(state = state, streamingState = streamingState)
+
+            // ReactionEvent is handled by the ViewModel — purely cosmetic animation
+            is WsEvent.ReactionEvent -> ReducerResult(state = state, streamingState = streamingState)
         }
 
     // ── GatewayReady ──────────────────────────────────────────────────