Nutrient
fun NutrientPopup(onDismissRequest: () -> Unit, modifier: Modifier = Modifier, offset: IntOffset = IntOffset.Zero, content: @Composable () -> Unit)
Anchored popup primitive (POPUP-1 / P1-9) that toolbar submenus and the text-selection popup will build on in later phases. Owns anchoring with edge-overflow correction (clamp into the window, flip above the anchor when there isn't room below), themed chrome from UiTheme's popup colors, and dismissal (outside tap / back).
Reuses the framework Popup + a PopupPositionProvider rather than reimplementing windowing. Positioned relative to the composable that hosts it (call it inside the anchor's Box), exactly like DropdownMenu.
Pixel-parity with the legacy AppCompat popups is verified by the Paparazzi goldens (TEST-2/3) once that harness lands.