refactor: make isHandleDisabled required in context

- Change isHandleDisabled from optional to required in SliderContextProps
- Remove unnecessary null checks in Tracks and Handle components

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 刘欢

src/Handles/Handle.tsx

@@ -68,8 +68,7 @@ const Handle = React.forwardRef<HTMLDivElement, HandleProps>((props, ref) => {
     isHandleDisabled,
   } = React.useContext(SliderContext);
 
-  const handleDisabled =
-    globalDisabled || (isHandleDisabled ? isHandleDisabled(valueIndex) : false);
+  const handleDisabled = globalDisabled || isHandleDisabled(valueIndex);
 
   const handlePrefixCls = `${prefixCls}-handle`;
 

src/Tracks/index.tsx

@@ -18,7 +18,6 @@ const Tracks: React.FC<TrackProps> = (props) => {
   const { included, range, min, styles, classNames, isHandleDisabled } = React.useContext(SliderContext);
 
   const hasDisabledHandle = React.useMemo(() => {
-    if (!isHandleDisabled) return false;
     for (let i = 0; i < values.length; i++) {
       if (isHandleDisabled(i)) return true;
     }

src/context.ts

@@ -19,7 +19,7 @@ export interface SliderContextProps {
   ariaValueTextFormatterForHandle?: AriaValueFormat | AriaValueFormat[];
   classNames: SliderClassNames;
   styles: SliderStyles;
-  isHandleDisabled?: (index: number) => boolean;
+  isHandleDisabled: (index: number) => boolean;
 }
 
 const SliderContext = React.createContext<SliderContextProps>({