feat(storage): support deleting backends and improve admin UI

- Implement storage backend deletion, which automatically resets default storage settings and user-specific overrides when a backend is removed.
- Add unit tests covering the delete action and its cleanup side effects.
- Improve admin UI responsiveness, fixing table scrolling, flex wrapping, and text truncation for long storage backend names.
- Update security documentation to clarify trusted proxy configurations and explain how trusted proxies are protected from automatic bans.

backend/libs/middleware/client_ip.go

@@ -0,0 +1,16 @@
+package middleware
+
+import (
+	"net/http"
+
+	"warpbox.dev/backend/libs/services"
+)
+
+func ClientIP(trustedProxies []string) Middleware {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			ip := services.ClientIP(r.RemoteAddr, r.Header.Get("X-Forwarded-For"), r.Header.Get("X-Real-IP"), trustedProxies)
+			next.ServeHTTP(w, services.WithClientIP(r, ip))
+		})
+	}
+}