feat(import): 用 Excel 格式替换 CSV 导入

- 删除 CSV 解析代码，新增 Excel 解析器 (excelize)

- 更新 IoT 卡和设备导入任务处理器

- 更新 API 路由文档和前端接入指南

- 归档变更到 openspec/changes/archive/

- 同步 delta specs 到 main specs

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/stretchr/testify v1.11.1
 	github.com/swaggest/openapi-go v0.2.60
 	github.com/valyala/fasthttp v1.66.0
+	github.com/xuri/excelize/v2 v2.8.1
 	go.uber.org/zap v1.27.1
 	golang.org/x/crypto v0.47.0
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
@@ -60,11 +61,14 @@ require (
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.16 // indirect
 	github.com/mattn/go-sqlite3 v1.14.22 // indirect
+	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
 	github.com/patrickmn/go-cache v2.1.0+incompatible // indirect
 	github.com/pelletier/go-toml/v2 v2.2.4 // indirect
 	github.com/philhofer/fwd v1.1.3-0.20240916144458-20a13a1f6b7c // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/richardlehane/mscfb v1.0.4 // indirect
+	github.com/richardlehane/msoleps v1.0.4 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/robfig/cron/v3 v3.0.1 // indirect
 	github.com/rogpeppe/go-internal v1.13.1 // indirect
@@ -81,12 +85,15 @@ require (
 	github.com/tinylib/msgp v1.2.5 // indirect
 	github.com/twitchyliquid64/golang-asm v0.15.1 // indirect
 	github.com/valyala/bytebufferpool v1.0.0 // indirect
+	github.com/xuri/efp v0.0.1 // indirect
+	github.com/xuri/nfp v0.0.2-0.20250530014748-2ddeb826f9a9 // indirect
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.54.0 // indirect
 	go.opentelemetry.io/otel v1.39.0 // indirect
 	go.opentelemetry.io/otel/trace v1.39.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/arch v0.0.0-20210923205945-b76863e36670 // indirect
+	golang.org/x/net v0.48.0 // indirect
 	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.40.0 // indirect
 	golang.org/x/text v0.33.0 // indirect