Flatten hello/ and question/ extension examples to single files

packages/coding-agent/examples/extensions/hello.ts

@@ -0,0 +1,25 @@
+/**
+ * Hello Tool - Minimal custom tool example
+ */
+
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+import { Type } from "@sinclair/typebox";
+
+export default function (pi: ExtensionAPI) {
+	pi.registerTool({
+		name: "hello",
+		label: "Hello",
+		description: "A simple greeting tool",
+		parameters: Type.Object({
+			name: Type.String({ description: "Name to greet" }),
+		}),
+
+		async execute(_toolCallId, params, _onUpdate, _ctx, _signal) {
+			const { name } = params as { name: string };
+			return {
+				content: [{ type: "text", text: `Hello, ${name}!` }],
+				details: { greeted: name },
+			};
+		},
+	});
+}