feat(chat): support hierarchical nested subtasks in Todos via parent property (#1018) (#1028)

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

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

@@ -1,6 +1,7 @@
 package com.m57.hermescontrol.data.ws
 
 import android.util.Log
+import com.m57.hermescontrol.ui.chat.extractTodosFromMap
 
 /**
  * Converts raw [JsonRpcResponse] objects into typed [WsEvent] instances.
@@ -189,6 +190,15 @@ object EventParser {
                 WsEvent.SessionUsage(payload, sessionId)
             }
 
+            "todo.updated" -> {
+                val revision =
+                    (payload?.get("revision") as? Number)?.toInt()
+                        ?: (params["revision"] as? Number)?.toInt()
+                val rawTodos = payload ?: params
+                val todos = extractTodosFromMap(rawTodos) ?: emptyList()
+                WsEvent.TodoUpdated(todos, revision, sessionId)
+            }
+
             "reaction" -> {
                 val kind = payload?.get("kind") as? String ?: ""
                 WsEvent.ReactionEvent(kind)

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

@@ -1,5 +1,7 @@
 package com.m57.hermescontrol.data.ws
 
+import com.m57.hermescontrol.ui.chat.TodoItem
+
 /** Parsed WebSocket events emitted by [HermesWsClient]. */
 sealed class WsEvent {
     // ── Gateway lifecycle ────────────────────────────────────────────────
@@ -183,6 +185,17 @@ sealed class WsEvent {
         val sessionId: String? = null,
     ) : WsEvent()
 
+    /**
+     * Revisioned todo snapshot event emitted by backend todo tool updates (issue #1018).
+     * Event: `todo.updated`
+     * Payload: `{ "todos": [...], "revision": Int }`
+     */
+    data class TodoUpdated(
+        val todos: List<TodoItem> = emptyList(),
+        val revision: Int? = null,
+        val sessionId: String? = null,
+    ) : WsEvent()
+
     // ── RPC responses ────────────────────────────────────────────────────
 
     data class RpcResult(