Flatten hello/ and question/ extension examples to single files

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

@@ -1,21 +0,0 @@
-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 },
-			};
-		},
-	});
-}