chore: 修复 import 路径为 xiaomihome/miot，补充 README 项目文档

go.mod 模块名为 xiaomihome，将所有内部 import 从 "miot" 更新为
"xiaomihome/miot"，涉及所有测试文件和示例文件。新增 README.md 项目
介绍文档（架构概览、模块说明、移植进度等）。新增 ARCH_PLAN.md 架构
设计文档。

miot/examples/cloud_devices/main.go

@@ -6,8 +6,8 @@ import (
 	"fmt"
 	"os"
 
-	"miot"
-	"miot/examples/config"
+	"xiaomihome/miot"
+	"xiaomihome/miot/examples/config"
 )
 
 func main() {

miot/examples/cloud_oauth/main.go

@@ -6,8 +6,8 @@ import (
 	"encoding/json"
 	"fmt"
 
-	"miot"
-	"miot/examples/config"
+	"xiaomihome/miot"
+	"xiaomihome/miot/examples/config"
 )
 
 func main() {

miot/examples/config/config.go

@@ -9,7 +9,7 @@ import (
 	"os"
 	"time"
 
-	"miot"
+	"xiaomihome/miot"
 )
 
 // AuthInfo mirrors the OAuth token stored in Python miot_config/{uid}_{cloud_server}.dict.
@@ -36,10 +36,10 @@ type Config struct {
 	RedirectURL string `json:"redirect_url"` // OAuth callback URL
 
 	// === entry_data optional fields ===
-	Language     string `json:"language"`      // integration_language: en/zh-Hans/de etc.
-	CtrlMode     string `json:"ctrl_mode"`     // auto/cloud/lan
-	StoragePath  string `json:"storage_path"`  // data directory for miot_storage
-	NickName     string `json:"nick_name"`     // display name in Xiaomi Home
+	Language    string `json:"language"`     // integration_language: en/zh-Hans/de etc.
+	CtrlMode    string `json:"ctrl_mode"`    // auto/cloud/lan
+	StoragePath string `json:"storage_path"` // data directory for miot_storage
+	NickName    string `json:"nick_name"`    // display name in Xiaomi Home
 
 	// internal
 	configPath string // path to this config file

miot/examples/full_client/main.go

@@ -8,8 +8,8 @@ import (
 	"os/signal"
 	"time"
 
-	"miot"
-	"miot/examples/config"
+	"xiaomihome/miot"
+	"xiaomihome/miot/examples/config"
 )
 
 func main() {

miot/examples/lan_control/main.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"time"
 
-	"miot"
+	"xiaomihome/miot"
 )
 
 func main() {

miot/examples/mdns_discovery/main.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"time"
 
-	"miot"
+	"xiaomihome/miot"
 )
 
 func main() {

miot/examples/mips_subscribe/main.go

@@ -7,8 +7,8 @@ import (
 	"os"
 	"time"
 
-	"miot"
-	"miot/examples/config"
+	"xiaomihome/miot"
+	"xiaomihome/miot/examples/config"
 )
 
 func main() {

miot/examples/network_monitor/main.go

@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"time"
 
-	"miot"
+	"xiaomihome/miot"
 )
 
 func main() {

miot/examples/spec_parser/main.go

@@ -5,7 +5,7 @@ package main
 import (
 	"fmt"
 
-	"miot"
+	"xiaomihome/miot"
 )
 
 func main() {

miot/examples/storage_manage/main.go

@@ -5,8 +5,8 @@ package main
 import (
 	"fmt"
 
-	"miot"
-	"miot/examples/config"
+	"xiaomihome/miot"
+	"xiaomihome/miot/examples/config"
 )
 
 func main() {