CngxChipStripRovingOptions

Element hosting the chip wrappers. Read lazily at focusAt() time so the controller doesn't depend on view-init timing. null is a legitimate idle state - the controller becomes a no-op focuser.

Reactive length of the chip list. When this count shrinks below activeIndex, the controller clamps the active index so focus never dangles at a removed position.

Attribute name used to identify each chip wrapper. Combined with the active index into a [attr="index"] query. Defaults to 'data-reorder-index' (matches CngxReorder's own item contract, so a single DOM hook covers both the reorder directive and this roving controller).