feat(storage): add S3 backend support and advanced upload limits

- Introduce S3-compatible storage backend support using minio-go.
- Add configuration options for local storage limits, box limits, and rate limiting.
- Implement storage backend selection (local vs S3) for anonymous and registered users.
- Add an `/admin/storage` management interface.
- Update documentation and environment examples with the new configuration variables.

backend/libs/handlers/pages.go

@@ -2,6 +2,7 @@ package handlers
 
 import (
 	"net/http"
+	"strconv"
 
 	"warpbox.dev/backend/libs/services"
 	"warpbox.dev/backend/libs/web"
@@ -61,11 +62,16 @@ func (a *App) homeUploadPolicyLabels(settings services.UploadPolicySettings, use
 		if !settings.AnonymousUploadsEnabled {
 			return "Anonymous uploads disabled", "Sign in to upload files."
 		}
-		return services.FormatMegabytesLabel(settings.AnonymousMaxUploadMB), "Daily anonymous cap: " + services.FormatMegabytesLabel(settings.AnonymousDailyUploadMB) + " per IP."
+		return services.FormatMegabytesLabel(settings.AnonymousMaxUploadMB), "Daily anonymous cap: " + services.FormatMegabytesLabel(settings.AnonymousDailyUploadMB) + " per IP · " + strconv.Itoa(settings.AnonymousMaxDays) + " day max."
 	}
-	quotaMB := settings.DefaultUserStorageMB
-	if user.StorageQuotaMB != nil {
-		quotaMB = *user.StorageQuotaMB
+	policy := a.settingsService.EffectivePolicyForUser(settings, user)
+	maxUpload := a.uploadService.MaxUploadSizeLabel()
+	if policy.MaxUploadMB > 0 {
+		maxUpload = services.FormatMegabytesLabel(policy.MaxUploadMB)
 	}
-	return a.uploadService.MaxUploadSizeLabel(), "Daily cap: " + services.FormatMegabytesLabel(settings.UserDailyUploadMB) + " · Storage quota: " + services.FormatMegabytesLabel(quotaMB) + "."
+	quota := "unlimited"
+	if policy.StorageQuotaSet {
+		quota = services.FormatMegabytesLabel(policy.StorageQuotaMB)
+	}
+	return maxUpload, "Daily cap: " + services.FormatMegabytesLabel(policy.DailyUploadMB) + " · Storage quota: " + quota + " · " + strconv.Itoa(policy.MaxDays) + " day max."
 }