refactor(benchmark): replace whoami service with bench server

- Updated dev.compose.yml to define a new bench service that serves 4096 bytes of random data.
- Modified configurations for Traefik, Caddy, and Nginx to route traffic to the new bench service.
- Added Dockerfile and Go application for the bench server, including necessary Go modules.
- Updated benchmark script to target the new bench service endpoint.

cmd/bench_server/Dockerfile

@@ -0,0 +1,18 @@
+FROM golang:1.25.5-alpine AS builder
+
+HEALTHCHECK NONE
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+COPY main.go ./
+
+RUN go build -o bench_server main.go
+
+FROM scratch
+
+COPY --from=builder /src/bench_server /app/run
+
+USER 1001:1001
+
+CMD ["/app/run"]

cmd/bench_server/go.mod

@@ -0,0 +1,3 @@
+module github.com/yusing/godoxy/cmd/bench_server
+
+go 1.25.5

cmd/bench_server/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"math/rand/v2"
+)
+
+var printables = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+var random = make([]byte, 4096)
+
+func init() {
+	for i := range random {
+		random[i] = printables[rand.IntN(len(printables))]
+	}
+}
+
+func main() {
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Write(random)
+	})
+
+	server := &http.Server{
+		Addr:    ":80",
+		Handler: handler,
+	}
+
+	log.Println("Bench server listening on :80")
+	if err := server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
+		log.Fatalf("ListenAndServe: %v", err)
+	}
+}