feat(ui): add clear queue flow and expose ISO expiry

- Add `formatBrowserTime()` and include ISO-8601 `expires_at` in box status JSON and `ExpiresAtISO` in the box view for browser-friendly rendering.
- Refresh UI styling (switch to MonoCraft/PixelOperatorMono, tweak base font size) and treat `aria-disabled="true"` like `disabled` for consistent button states.
- Introduce a clear-queue action with confirmation to reset upload state, unlock controls, and provide user feedback.feat(ui): add clear queue flow and expose ISO expiry

- Add `formatBrowserTime()` and include ISO-8601 `expires_at` in box status JSON and `ExpiresAtISO` in the box view for browser-friendly rendering.
- Refresh UI styling (switch to MonoCraft/PixelOperatorMono, tweak base font size) and treat `aria-disabled="true"` like `disabled` for consistent button states.
- Introduce a clear-queue action with confirmation to reset upload state, unlock controls, and provide user feedback.

lib/server/handlers.go

@@ -21,6 +21,13 @@ const boxAuthCookiePrefix = "warpbox_box_"
 
 var oneTimeDownloadLocks sync.Map
 
+func formatBrowserTime(value time.Time) string {
+	if value.IsZero() {
+		return ""
+	}
+	return value.UTC().Format(time.RFC3339)
+}
+
 func (app *App) handleIndex(ctx *gin.Context) {
 	ctx.HTML(http.StatusOK, "index.html", gin.H{
 		"RetentionOptions": app.retentionOptions(),
@@ -63,6 +70,7 @@ func (app *App) handleShowBox(ctx *gin.Context) {
 		"PollMS":         app.config.BoxPollIntervalMS,
 		"RetentionLabel": manifest.RetentionLabel,
 		"ExpiresAt":      manifest.ExpiresAt,
+		"ExpiresAtISO":   formatBrowserTime(manifest.ExpiresAt),
 	})
 }
 
@@ -140,7 +148,8 @@ func (app *App) handleBoxStatus(ctx *gin.Context) {
 		return
 	}
 
-	if _, _, ok := app.authorizeBoxRequest(ctx, boxID, false); !ok {
+	manifest, _, ok := app.authorizeBoxRequest(ctx, boxID, false)
+	if !ok {
 		return
 	}
 
@@ -150,7 +159,7 @@ func (app *App) handleBoxStatus(ctx *gin.Context) {
 		return
 	}
 
-	ctx.JSON(http.StatusOK, gin.H{"box_id": boxID, "files": files})
+	ctx.JSON(http.StatusOK, gin.H{"box_id": boxID, "expires_at": formatBrowserTime(manifest.ExpiresAt), "files": files})
 }
 
 func (app *App) handleDownloadBox(ctx *gin.Context) {