feat(deploy): M11 单二进制装配（cmd/cyrene 全链路 wire + go:embed 前端 + 外置 dist 覆盖 + 优雅关闭 + SPA 静态服务）；前端 build 拷到 internal/webui/dist

internal/webui/webui.go

@@ -0,0 +1,47 @@
+// Package webui embeds the built frontend SPA (frontend/web/dist) into the
+// single Cyrene binary and exposes it as a filesystem. It is the default asset
+// source for the gateway's static server; a deployer may still drop an external
+// dist directory next to the process to override it (see internal/services/
+// gateway and cmd/cyrene).
+//
+// The embedded tree is rooted at the dist directory, so index.html and
+// assets/* appear at the filesystem root. Build the frontend with
+// `cd frontend/web && npm run build` (which also syncs dist into this package)
+// before running `go build ./...`; the //go:embed directive fails to compile
+// when the dist directory is absent.
+package webui
+
+import (
+	"embed"
+	"io/fs"
+)
+
+// dist holds the built SPA. It is generated by the frontend build and must
+// exist for the package to compile.
+//
+//go:embed all:dist
+var dist embed.FS
+
+// Assets returns the embedded dist as an fs.FS rooted at the dist directory.
+// The returned FS is read-only and safe for concurrent use.
+func Assets() fs.FS {
+	sub, err := fs.Sub(dist, "dist")
+	if err != nil {
+		// The embed directive guarantees dist exists, so this cannot fail; a
+		// panic here is a programming error, not a runtime condition.
+		panic("webui: dist embed missing: " + err.Error())
+	}
+	return sub
+}
+
+// Open opens a file under the dist root by its slash-separated (or
+// filesystem) name. It is a convenience over Assets().Open.
+func Open(name string) (fs.File, error) {
+	return Assets().Open(name)
+}
+
+// Exists reports whether a file or directory exists within the embedded dist.
+func Exists(path string) bool {
+	_, err := fs.Stat(Assets(), path)
+	return err == nil
+}