Lululemon Athletica Inc. (NASDAQ:LULU) shares are riding high, advancing nearly 3% over the last week, on news of activist involvement and an earnings beat, but a key fundamental indicator suggests the retailer’s operational health remains fragile.Quality Metric TumblesWhile legendary investors Michael Burry and Paul Singer's Elliott Investment Management pile in, Benzinga Edge’s Stock Rankings‘ quality” score for the stock has dropped week-on-week, flashing a warning signal beneath the hype.Lululemon’s Qua ...