webui, termui: use 〰️ for tool call failures

Replaces 🙈 and 🔔 and ❌ and ⚠️.

Maybe this one will stick. It's low key and a little wobbly.

Co-Authored-By: sketch <hello@sketch.dev>
diff --git a/webui/src/web-components/sketch-tool-card.ts b/webui/src/web-components/sketch-tool-card.ts
index b4bdd64..0181673 100644
--- a/webui/src/web-components/sketch-tool-card.ts
+++ b/webui/src/web-components/sketch-tool-card.ts
@@ -212,7 +212,7 @@
     >`;
     if (this.toolCall?.result_message) {
       statusIcon = this.toolCall?.result_message.tool_error
-        ? html`<span class="tool-call-status tool-error">🔔</span>`
+        ? html`<span class="tool-call-status tool-error">〰️</span>`
         : html`<span class="tool-call-status tool-success">✓</span>`;
     }