feat: Implement initial full-stack application structure including frontend pages, components, hooks, API integration, and backend services for account pooling and management.

backend/internal/web/dev.go

@@ -0,0 +1,18 @@
+//go:build !embed
+// +build !embed
+
+package web
+
+import (
+	"net/http"
+)
+
+// GetFileSystem 返回 nil（开发模式不嵌入前端）
+func GetFileSystem() http.FileSystem {
+	return nil
+}
+
+// IsEmbedded 返回前端是否已嵌入
+func IsEmbedded() bool {
+	return false
+}