chore: 提交高层 xiaomi 封装库及示例

- 新增 xiaomi/examples/ 下 8 个示例程序（用户/家庭查询、设备列表、开关/灯光/空调控制、属性订阅、高级过滤分类、SPEC 解析）
- miot_client_sub.go: 重构 SubProp/SubEvent，使用 buildPropTopic/buildEventTopic 支持通配符订阅（siid/piid=0 → +），并修复锁顺序问题（将 RequestRefreshProp 移到 Lock 外）
- spec_parser.go: 新增 downloadSpecFile 方法，本地 SPEC 文件缺失时自动从 miot-spec.org 下载
- ARCH_PLAN.md: 架构设计从 Proposed 更新为 Accepted（v1.0→v1.1），补充设备分类/工厂/SPEC 映射等模块设计
- xiaomi/: 新增 miot 上层强类型封装模块，包含 Client 主入口、用户/家庭/设备 API、属性读写、动作调用、订阅通知，以及 devices/ 设备控制抽象（Switch/Light/AirConditioner/Fan/Cover/Humidifier/Vacuum/WaterHeater/Thermostat）和 specs/ SPEC 查询辅助
- 更多 xiaomi 示例（风扇/窗帘/传感器控制）

xiaomi/examples/04_light_control/data/cert/mihome_ca.cert

@@ -0,0 +1,21 @@
+-----BEGIN CERTIFICATE-----
+MIIBazCCAQ+gAwIBAgIEA/UKYDAMBggqhkjOPQQDAgUAMCIxEzARBgNVBAoTCk1p
+amlhIFJvb3QxCzAJBgNVBAYTAkNOMCAXDTE2MTEyMzAxMzk0NVoYDzIwNjYxMTEx
+MDEzOTQ1WjAiMRMwEQYDVQQKEwpNaWppYSBSb290MQswCQYDVQQGEwJDTjBZMBMG
+ByqGSM49AgEGCCqGSM49AwEHA0IABL71iwLa4//4VBqgRI+6xE23xpovqPCxtv96
+2VHbZij61/Ag6jmi7oZ/3Xg/3C+whglcwoUEE6KALGJ9vccV9PmjLzAtMAwGA1Ud
+EwQFMAMBAf8wHQYDVR0OBBYEFJa3onw5sblmM6n40QmyAGDI5sURMAwGCCqGSM49
+BAMCBQADSAAwRQIgchciK9h6tZmfrP8Ka6KziQ4Lv3hKfrHtAZXMHPda4IYCIQCG
+az93ggFcbrG9u2wixjx1HKW4DUA5NXZG0wWQTpJTbQ==
+-----END CERTIFICATE-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

xiaomi/examples/04_light_control/main.go

@@ -0,0 +1,108 @@
+// Package main demonstrates light device control - brightness, color temperature, RGB, and state subscription.
+// 运行前提：已配置环境变量 XIAOMI_CLIENT_ID / XIAOMI_CLIENT_SECRET / XIAOMI_ACCESS_TOKEN。
+package main
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"xiaomihome/xiaomi"
+	"xiaomihome/xiaomi/devices"
+	miotconfig "xiaomihome/miot/examples/config"
+)
+
+func main() {
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	cfg, err := miotconfig.LoadConfig("../../../miot/examples/config.json")
+	if err != nil {
+		log.Fatal("请先运行 miot/examples/cloud_oauth 获取 token:", err)
+	}
+
+	client, err := xiaomi.NewClient(ctx, xiaomi.Config{
+		ClientSecret: "",
+		AccessToken:  cfg.AuthInfo.AccessToken,
+		UID:          cfg.UID,
+		UUID:         cfg.UUID,
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer client.Close()
+
+	const targetDID = "2169700407"
+
+	info, err := client.GetDevice(ctx, targetDID)
+	if err != nil {
+		log.Fatalf("获取设备 %s 失败: %v", targetDID, err)
+	}
+
+	lt, err := devices.NewLight(client, info)
+	if err != nil {
+		log.Fatalf("创建 Light 失败: %v", err)
+	}
+
+	log.Printf("灯光: %s (DID: %s, 型号: %s)", info.Name, info.DID, info.Model)
+
+	log.Println("开启灯光...")
+	if err := lt.TurnOn(ctx); err != nil {
+		log.Printf("开启失败: %v", err)
+	}
+
+	log.Println("设置亮度...")
+	if err := lt.SetBrightness(ctx, 50); err != nil {
+		log.Printf("设置亮度失败（可能不支持）: %v", err)
+	}
+	brightness, err := lt.GetBrightness(ctx)
+	if err != nil {
+		log.Printf("获取亮度失败: %v", err)
+	} else {
+		log.Printf("当前亮度: %d", brightness)
+	}
+
+	time.Sleep(1 * time.Second)
+
+	log.Println("设置色温 4000K...")
+	if err := lt.SetColorTemp(ctx, 4000); err != nil {
+		log.Printf("设置色温失败（可能不支持）: %v", err)
+	}
+	colorTemp, err := lt.GetColorTemp(ctx)
+	if err != nil {
+		log.Printf("获取色温失败: %v", err)
+	} else {
+		log.Printf("当前色温: %dK", colorTemp)
+	}
+
+	time.Sleep(1 * time.Second)
+
+	log.Println("设置颜色 R=255 G=100 B=50...")
+	if err := lt.SetColor(ctx, 255, 100, 50); err != nil {
+		log.Printf("设置颜色失败（可能不支持）: %v", err)
+	}
+	r, g, b, err := lt.GetColor(ctx)
+	if err != nil {
+		log.Printf("获取颜色失败: %v", err)
+	} else {
+		log.Printf("当前颜色: R=%d G=%d B=%d", r, g, b)
+	}
+
+	subID, err := lt.OnStateChanged(func(state devices.LightState) {
+		log.Printf("灯光状态变化: power=%v brightness=%d colorTemp=%dK rgb=[%d,%d,%d]",
+			state.Power, state.Brightness, state.ColorTemp,
+			state.ColorRGB[0], state.ColorRGB[1], state.ColorRGB[2])
+	})
+	if err != nil {
+		log.Printf("订阅状态失败: %v", err)
+	} else {
+		log.Printf("已订阅灯光状态: subID=%s", subID)
+	}
+
+	log.Println("执行 Toggle...")
+	if err := lt.Toggle(ctx); err != nil {
+		log.Printf("Toggle 失败: %v", err)
+	}
+
+	log.Println("灯光控制演示完毕")
+}