feat: initialize warpbox.dev project structure and backend

Initialize the repository with the core Go backend architecture and a frontend mockup for warpbox.dev, a self-hosted file-sharing application.

- Set up Go backend modules for configuration, HTTP server, middleware, handlers, and templates.
- Add local development scripts, environment templates, and basic project configuration.
- Include a React-based frontend mockup under the docs directory.

backend/libs/web/renderer.go

@@ -0,0 +1,79 @@
+package web
+
+import (
+	"html/template"
+	"net/http"
+	"path/filepath"
+	"time"
+)
+
+type Renderer struct {
+	templates map[string]*template.Template
+	appName   string
+	baseURL   string
+}
+
+type PageData struct {
+	AppName     string
+	BaseURL     string
+	Title       string
+	Description string
+	CurrentYear int
+	Data        any
+}
+
+func NewRenderer(templateDir, appName, baseURL string) (*Renderer, error) {
+	layouts, err := filepath.Glob(filepath.Join(templateDir, "layouts", "*.gohtml"))
+	if err != nil {
+		return nil, err
+	}
+
+	partials, err := filepath.Glob(filepath.Join(templateDir, "partials", "*.gohtml"))
+	if err != nil {
+		return nil, err
+	}
+
+	pages, err := filepath.Glob(filepath.Join(templateDir, "pages", "*.gohtml"))
+	if err != nil {
+		return nil, err
+	}
+
+	templates := make(map[string]*template.Template, len(pages))
+	for _, page := range pages {
+		files := append([]string{}, layouts...)
+		files = append(files, partials...)
+		files = append(files, page)
+
+		parsed, err := template.ParseFiles(files...)
+		if err != nil {
+			return nil, err
+		}
+
+		templates[filepath.Base(page)] = parsed
+	}
+
+	return &Renderer{
+		templates: templates,
+		appName:   appName,
+		baseURL:   baseURL,
+	}, nil
+}
+
+func (r *Renderer) Render(w http.ResponseWriter, status int, page string, data PageData) {
+	data.AppName = r.appName
+	data.BaseURL = r.baseURL
+	data.CurrentYear = time.Now().Year()
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.WriteHeader(status)
+
+	tmpl, ok := r.templates[page]
+	if !ok {
+		http.Error(w, "template not found", http.StatusInternalServerError)
+		return
+	}
+
+	if err := tmpl.ExecuteTemplate(w, page, data); err != nil {
+		http.Error(w, "template render error", http.StatusInternalServerError)
+	}
+}