refactor: remove dead tangent handle variant

The { kind: "tangent" } MaskHandleId variant was never constructed — neither
getFreeformDisplayHandles nor any other code ever produced a tangent handle
object. The in/out control-arm branches in computeFreeformParamUpdate, the
tangent case in maskHandleIdKey, and the CUSTOM_MASK_TANGENT_SIZE rendering
path in mask-handles.tsx were all unreachable. Removed all four dead paths
and removed "tangent" from MaskHandleKind.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/web/src/masks/freeform/definition.ts

@@ -257,7 +257,7 @@ function computeFreeformParamUpdate({
 		};
 	}
 
-	if (handleId.kind !== "anchor" && handleId.kind !== "tangent") {
+	if (handleId.kind !== "anchor") {
 		return {};
 	}
 
@@ -279,29 +279,11 @@ function computeFreeformParamUpdate({
 		path: updateFreeformPathMaskPoint({
 			points,
 			pointId: handleId.pointId,
-			updater: (point) => {
-				if (handleId.kind === "anchor") {
-					return {
-						...point,
-						x: localPoint.x,
-						y: localPoint.y,
-					};
-				}
-
-				if (handleId.side === "in") {
-					return {
-						...point,
-						inX: localPoint.x - point.x,
-						inY: localPoint.y - point.y,
-					};
-				}
-
-				return {
-					...point,
-					outX: localPoint.x - point.x,
-					outY: localPoint.y - point.y,
-				};
-			},
+			updater: (point) => ({
+				...point,
+				x: localPoint.x,
+				y: localPoint.y,
+			}),
 		}),
 	};
 }

apps/web/src/masks/types.ts

@@ -187,11 +187,10 @@ export interface MaskFeatures {
 
 export type MaskHandleIcon = "rotate" | "feather";
 
-export type MaskHandleKind = "corner" | "edge" | "icon" | "point" | "tangent";
+export type MaskHandleKind = "corner" | "edge" | "icon" | "point";
 
 type Side = "left" | "right" | "top" | "bottom";
 type CornerXY = { x: "left" | "right"; y: "top" | "bottom" };
-type CustomTangent = "in" | "out";
 
 export type MaskHandleId =
 	| { kind: "position" }
@@ -201,7 +200,6 @@ export type MaskHandleId =
 	| { kind: "edge"; side: Side }
 	| { kind: "corner"; corner: CornerXY }
 	| { kind: "anchor"; pointId: string }
-	| { kind: "tangent"; pointId: string; side: CustomTangent }
 	| { kind: "segment"; index: number };
 
 export function maskHandleIdKey({ id }: { id: MaskHandleId }): string {
@@ -217,8 +215,6 @@ export function maskHandleIdKey({ id }: { id: MaskHandleId }): string {
 			return `${id.corner.y}-${id.corner.x}`;
 		case "anchor":
 			return `point:${id.pointId}:anchor`;
-		case "tangent":
-			return `point:${id.pointId}:${id.side}`;
 		case "segment":
 			return `segment:${id.index}`;
 	}

apps/web/src/preview/components/mask-handles.tsx

@@ -17,7 +17,6 @@ import {
 } from "./handle-primitives";
 
 const CUSTOM_MASK_ANCHOR_SIZE = 7;
-const CUSTOM_MASK_TANGENT_SIZE = 6;
 import { Rotate01Icon, FeatherIcon } from "@hugeicons/core-free-icons";
 
 export function MaskHandles({
@@ -258,25 +257,21 @@ export function MaskHandles({
 					);
 				}
 
-				if (handle.kind === "point" || handle.kind === "tangent") {
-					return (
-						<CircleHandle
-							key={key}
-							screen={screen}
-							size={
-								handle.kind === "tangent"
-									? CUSTOM_MASK_TANGENT_SIZE
-									: CUSTOM_MASK_ANCHOR_SIZE
-							}
-							isSelected={handle.isSelected}
-							onPointerDown={(event) =>
-								handleMaskPointerDown({ event, handleId: handle.id })
-							}
-							onPointerMove={onPointerMove}
-							onPointerUp={onPointerUp}
-						/>
-					);
-				}
+			if (handle.kind === "point") {
+				return (
+					<CircleHandle
+						key={key}
+						screen={screen}
+						size={CUSTOM_MASK_ANCHOR_SIZE}
+						isSelected={handle.isSelected}
+						onPointerDown={(event) =>
+							handleMaskPointerDown({ event, handleId: handle.id })
+						}
+						onPointerMove={onPointerMove}
+						onPointerUp={onPointerUp}
+					/>
+				);
+			}
 
 				if (handle.kind === "corner") {
 					return (