Chilled Pineapple Mousse With Pistachios

Ingredients

• 2 1/4 ounces shelled, unsalted pistachios (1/2 cup)
• 9 graham crackers
• 1/4 cup granulated sugar
• 1/4 teaspoon salt
• 4 ounces (8 tablespoons) unsalted butter, melted
• 2 cans (20 ounces each) pineapple chunks, packed in syrup
• canned pineapple juice (up to 2 cups), as needed
• 2 tablespoons plus 2 teaspoons powdered gelatin (from three 1/4-ounce envelopes)
• 1/2 cup boiling water
• 2 teaspoons finely grated lemon zest
• 1/4 cup fresh lemon juice (from 2 lemons)
• 8 ounces (1 cup) cream cheese, softened
• 1 cup sour cream
• 1 1/4 cups confectioners' sugar
• 2 cups heavy cream
• lime sabayon, for serving