loop: add knowledge_base tool for on-demand information

The knowledge_base tool provides a way for agents to access specialized information
when needed. Initial topics include:

- sketch: how to use Sketch, including SSH, secrets, and file management
- go_iterators: information about Go's iterator feature added in Go 1.22

Co-Authored-By: sketch <hello@sketch.dev>
diff --git a/webui/src/web-components/sketch-tool-calls.ts b/webui/src/web-components/sketch-tool-calls.ts
index 5f416e1..99b0f21 100644
--- a/webui/src/web-components/sketch-tool-calls.ts
+++ b/webui/src/web-components/sketch-tool-calls.ts
@@ -4,6 +4,7 @@
 import { ToolCall } from "../types";
 import "./sketch-tool-card";
 import "./sketch-tool-card-take-screenshot";
+import "./sketch-tool-card-knowledge-base";
 
 @customElement("sketch-tool-calls")
 export class SketchToolCalls extends LitElement {
@@ -127,6 +128,11 @@
           .open=${open}
           .toolCall=${toolCall}
         ></sketch-tool-card-take-screenshot>`;
+      case "knowledge_base":
+        return html`<sketch-tool-card-knowledge-base
+          .open=${open}
+          .toolCall=${toolCall}
+        ></sketch-tool-card-knowledge-base>`;
     }
     return html`<sketch-tool-card-generic
       .open=${open}