webui: add agent state and status banner

Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: s9f1c332aad2630dfk
diff --git a/webui/src/web-components/sketch-app-shell.ts b/webui/src/web-components/sketch-app-shell.ts
index 9b3430d..7436671 100644
--- a/webui/src/web-components/sketch-app-shell.ts
+++ b/webui/src/web-components/sketch-app-shell.ts
@@ -964,6 +964,10 @@
             .agentState=${this.containerState?.agent_state}
             .llmCalls=${this.containerState?.outstanding_llm_calls || 0}
             .toolCalls=${this.containerState?.outstanding_tool_calls || []}
+            .isIdle=${this.messages.length > 0
+              ? this.messages[this.messages.length - 1]?.end_of_turn &&
+                !this.messages[this.messages.length - 1]?.parent_conversation_id
+              : true}
           ></sketch-call-status>
 
           <sketch-network-status