feat(sproutclaw): modularize webui, extensions, and agent config layout

Restructure local extensions into per-feature directories, split WebUI
into backend modules with slash commands and systemd support, and track
prompts/skills under .pi/agent for portable Gitea deployment.

Co-authored-by: Cursor <cursoragent@cursor.com>

.pi/agent/extensions/sproutclaw-setup/index.ts

@@ -0,0 +1,107 @@
+/**
+ * sproutclaw / mengya 命令安装扩展
+ *
+ * 启动后自动在 /usr/local/bin/ 下创建 mengya 和 sproutclaw 命令：
+ * - mengya：源码版（./pi-test.sh，tsx + src）
+ * - sproutclaw：构建版（./pi-built.sh，node dist/cli.js）
+ *
+ * 命令 /install-commands 可随时手动重装。
+ */
+
+import { existsSync, writeFileSync, chmodSync, readFileSync } from "node:fs";
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+
+const SPROUTCLAW_DIR = "/shumengya/project/agent/sproutclaw";
+const BIN_DIR = "/usr/local/bin";
+
+const COMMAND_LAUNCHERS: Record<string, string> = {
+	mengya: "./pi-test.sh",
+};
+
+function commandScript(launcher: string): string {
+	return `#!/usr/bin/env bash
+set -euo pipefail
+cd ${SPROUTCLAW_DIR}
+exec ${launcher} "$@"
+`;
+}
+
+function sproutclawScript(): string {
+	return `#!/usr/bin/env bash
+set -euo pipefail
+cd ${SPROUTCLAW_DIR}
+
+case "\${1:-}" in
+\tbuild)
+\t\tshift
+\t\texec npm run build "\$@"
+\t\t;;
+\trun)
+\t\tshift
+\t\texec ./pi-built.sh "\$@"
+\t\t;;
+\thelp|-h|--help)
+\t\tcat <<'EOF'
+sproutclaw - SproutClaw pi 构建版启动器
+
+用法:
+  sproutclaw              启动 pi（构建版）
+  sproutclaw run [args]   同 sproutclaw
+  sproutclaw build        从源码构建所有包
+
+其余参数透传给 pi，例如: sproutclaw --version
+EOF
+\t\t;;
+\t*)
+\t\texec ./pi-built.sh "\$@"
+\t\t;;
+esac
+`;
+}
+
+/** 创建或修复命令脚本 */
+function installCommand(name: string, script: string): boolean {
+	const path = `${BIN_DIR}/${name}`;
+
+	if (existsSync(path)) {
+		try {
+			const current = readFileSync(path, "utf-8");
+			if (current === script) return false;
+		} catch {
+			// Rewrite unreadable or invalid command files below.
+		}
+	}
+	writeFileSync(path, script, "utf-8");
+	chmodSync(path, 0o755);
+	return true;
+}
+
+export default function (pi: ExtensionAPI) {
+	for (const [name, launcher] of Object.entries(COMMAND_LAUNCHERS)) {
+		const created = installCommand(name, commandScript(launcher));
+		if (created) {
+			console.log(`[sproutclaw-setup] Created /usr/local/bin/${name}`);
+		}
+	}
+
+	const sproutclawCreated = installCommand("sproutclaw", sproutclawScript());
+	if (sproutclawCreated) {
+		console.log("[sproutclaw-setup] Created /usr/local/bin/sproutclaw");
+	}
+
+	pi.registerCommand("install-commands", {
+		description: "Install mengya (source) and sproutclaw (built) commands to /usr/local/bin",
+		handler: async (_args, ctx) => {
+			let count = 0;
+			for (const [name, launcher] of Object.entries(COMMAND_LAUNCHERS)) {
+				if (installCommand(name, commandScript(launcher))) count++;
+			}
+			if (installCommand("sproutclaw", sproutclawScript())) count++;
+			if (count > 0) {
+				ctx.ui.notify(`Installed ${count} command(s): mengya (source), sproutclaw (build/run)`, "success");
+			} else {
+				ctx.ui.notify("Commands already up to date", "info");
+			}
+		},
+	});
+}