refactor: reorganize models to pkg/model and add authentication module

- Move ORM models from internal/model to pkg/model organized by module (auth/k8s/registry)
- Add authentication module with login, user management handlers
- Update all import paths to use new model locations
- Add frontend auth pages (Login, UserManagement) and authStore
- Remove deprecated internal/model/model.go

internal/module/auth/wallpaper.go

@@ -0,0 +1,108 @@
+package auth
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"strings"
+	"sync"
+	"time"
+
+	"gitea.loveuer.com/loveuer/cluster/pkg/resp"
+	"github.com/go-resty/resty/v2"
+	"github.com/gofiber/fiber/v3"
+)
+
+func Wallpaper(ctx context.Context) fiber.Handler {
+	type Result struct {
+		Images []struct {
+			Startdate     string `json:"startdate"`
+			Fullstartdate string `json:"fullstartdate"`
+			Enddate       string `json:"enddate"`
+			URL           string `json:"url"`
+			Urlbase       string `json:"urlbase"`
+			Copyright     string `json:"copyright"`
+			Copyrightlink string `json:"copyrightlink"`
+			Title         string `json:"title"`
+			Quiz          string `json:"quiz"`
+			Wp            bool   `json:"wp"`
+			Hsh           string `json:"hsh"`
+			Drk           int    `json:"drk"`
+			Top           int    `json:"top"`
+			Bot           int    `json:"bot"`
+		} `json:"images"`
+	}
+
+	type Store struct {
+		sync.Mutex
+		Date    string            `json:"date"`
+		Body    []byte            `json:"body"`
+		Headers map[string]string `json:"headers"`
+	}
+
+	client := resty.New().SetTLSClientConfig(&tls.Config{InsecureSkipVerify: true})
+	apiUrl := "https://cn.bing.com/HPImageArchive.aspx?format=js&idx=0&n=1"
+	imgUrlPrefix := "https://cn.bing.com"
+	store := &Store{}
+
+	get := func() ([]byte, map[string]string, error) {
+		var (
+			err     error
+			rr      *resty.Response
+			result  = new(Result)
+			headers = make(map[string]string)
+			date    = time.Now().Format("2006-01-02")
+		)
+
+		if store.Date == date {
+			return store.Body, store.Headers, nil
+		}
+
+		if _, err = client.R().
+			SetResult(result).
+			Get(apiUrl); err != nil {
+			return nil, nil, fmt.Errorf("[BingWallpaper] get %s err: %w", apiUrl, err)
+		}
+
+		if len(result.Images) == 0 {
+			err = errors.New("[BingWallpaper]: image length = 0")
+			return nil, nil, err
+		}
+
+		address := fmt.Sprintf("%s%s", imgUrlPrefix, result.Images[0].URL)
+
+		if rr, err = client.R().
+			Get(address); err != nil {
+			err = fmt.Errorf("[BingWallpaper] get image body: %s err: %w", address, err)
+			return nil, nil, err
+		}
+
+		for key := range rr.Header() {
+			headers[key] = strings.Join(rr.Header()[key], ", ")
+		}
+
+		store.Lock()
+		store.Date = date
+		store.Body = rr.Body()
+		store.Headers = headers
+		store.Unlock()
+
+		return rr.Body(), headers, nil
+	}
+
+	return func(c fiber.Ctx) error {
+		bs, headers, err := get()
+		if err != nil {
+			return resp.R500(c, "", nil, err.Error())
+		}
+
+		for key := range headers {
+			c.Set(key, headers[key])
+		}
+
+		_, err = c.Write(bs)
+
+		return err
+	}
+}