feat: implement vim anchor moves and motion system

Added complete vim motion system with anchor moves:

New Files:
- src/useCursor/useVimMotions.ts: Vim motion processor
  - Handles number prefixes (counts)
  - Special 0 handling: anchor when alone, count when prefixed
  - Tracks last motion for repeat (.)

Anchor Moves:
- 0 or ^ → Move to start of row (col 0)
- $ → Move to end of row (col 8)
- gg → Move to top of column (row 0)
- G → Move to bottom of column (row 8)

Count Support:
- 5j → Move down 5 cells
- 10l → Move right 10 cells (bounded to 8)
- Works with all directional moves (h/j/k/l)

Repeat Motion:
- . → Repeat last motion with same count

Key Logic (0 handling):
- If 0 pressed with empty count buffer → anchor to start
- If 0 pressed with existing count → add to count (10j, 20k)
- Prevents conflict between anchor and counted moves

Updated:
- useCursor.ts: Integrated useVimMotions processor
- types.ts: Added Motion and VimMotionSystem types
- CursorManager: Added anchor and repeat methods

All moves respect 9x9 bounds with red flash on invalid.

src/useCursor/types.ts

@@ -1,9 +1,25 @@
 export type Coord = { row: number; col: number };
 
+export type Motion = { dr: number; dc: number; steps: number };
+
+export type VimMotionSystem = {
+  processKey: (key: string) => { type: 'move' | 'anchor' | 'repeat' | 'count'; data: any } | null;
+  resetCount: () => void;
+  getCount: () => number;
+  hasCount: () => boolean;
+  setLastMotion: (motion: Motion) => void;
+  repeatLastMotion: () => Motion | null;
+};
+
 export type CursorManager = {
   position: () => Coord;
   moveLeft: (count?: number) => void;
   moveRight: (count?: number) => void;
   moveUp: (count?: number) => void;
   moveDown: (count?: number) => void;
+  moveToStart: () => void;
+  moveToEnd: () => void;
+  moveToTop: () => void;
+  moveToBottom: () => void;
+  repeatLastMotion: () => void;
 };

src/useCursor/useCursor.ts

@@ -1,10 +1,12 @@
 import { useState, useEffect } from 'react';
 import type { Coord, CursorManager } from './types';
 import type { GameStatusManager } from '../useGameStatus/types';
+import { useVimMotions } from './useVimMotions';
 
 export function useCursor(gameStatusManager: GameStatusManager, containerRef: React.RefObject<HTMLDivElement | null>) {
   const [position, setPosition] = useState<Coord>({ row: 0, col: 0 });
   const { gameStatus } = gameStatusManager;
+  const vimMotions = useVimMotions();
 
   function flashInvalidMove(): void {
     const container = containerRef.current;
@@ -52,20 +54,78 @@ export function useCursor(gameStatusManager: GameStatusManager, containerRef: Re
     move(1, 0, count);
   }
 
+  function moveToStart(): void {
+    setPosition(prev => ({ ...prev, col: 0 }));
+  }
+
+  function moveToEnd(): void {
+    setPosition(prev => ({ ...prev, col: 8 }));
+  }
+
+  function moveToTop(): void {
+    setPosition(prev => ({ row: 0, col: prev.col }));
+  }
+
+  function moveToBottom(): void {
+    setPosition(prev => ({ row: 8, col: prev.col }));
+  }
+
+  function repeatLastMotion(): void {
+    const motion = vimMotions.repeatLastMotion();
+    if (!motion) return;
+
+    setPosition(currentPos => {
+      const newRow = currentPos.row + (motion.dr * motion.steps);
+      const newCol = currentPos.col + (motion.dc * motion.steps);
+
+      if (newRow < 0 || newRow > 8 || newCol < 0 || newCol > 8) {
+        flashInvalidMove();
+        return currentPos;
+      }
+
+      return { row: newRow, col: newCol };
+    });
+  }
+
   useEffect(() => {
     if (gameStatus !== 'started') return;
 
     function handleKeyDown(e: KeyboardEvent) {
       const key = e.key;
+      const result = vimMotions.processKey(key);
 
-      if (key === 'h') {
+      if (!result) return;
-        moveLeft();
+
-      } else if (key === 'j') {
+      switch (result.type) {
-        moveDown();
+        case 'move':
-      } else if (key === 'k') {
+          move(result.data.dr, result.data.dc, result.data.steps);
-        moveUp();
+          break;
-      } else if (key === 'l') {
+
-        moveRight();
+        case 'anchor':
+          switch (result.data) {
+            case 'start':
+              moveToStart();
+              break;
+            case 'end':
+              moveToEnd();
+              break;
+            case 'top':
+              moveToTop();
+              break;
+            case 'bottom':
+              moveToBottom();
+              break;
+          }
+          break;
+
+        case 'repeat':
+          if (result.data) {
+            move(result.data.dr, result.data.dc, result.data.steps);
+          }
+          break;
+
+        case 'count':
+          break;
       }
     }
 
@@ -79,6 +139,11 @@ export function useCursor(gameStatusManager: GameStatusManager, containerRef: Re
     moveRight,
     moveUp,
     moveDown,
+    moveToStart,
+    moveToEnd,
+    moveToTop,
+    moveToBottom,
+    repeatLastMotion,
   };
 
   return cursor;

src/useCursor/useVimMotions.ts

@@ -0,0 +1,104 @@
+import { useRef } from 'react';
+import type { VimMotionSystem, Motion } from './types';
+
+export function useVimMotions(): VimMotionSystem {
+  const countRef = useRef<string>('');
+  const lastMotionRef = useRef<Motion | null>(null);
+
+  function processKey(key: string): { type: 'move'|'anchor'|'repeat'|'count', data: any } | null {
+    if (key >= '0' && key <= '9') {
+      if (key === '0' && countRef.current === '') {
+        return { type: 'anchor', data: 'start' };
+      }
+      countRef.current += key;
+      return { type: 'count', data: key };
+    }
+
+    if (key === 'h') {
+      const motion = { dr: 0, dc: -1, steps: getCount() };
+      setLastMotion(motion);
+      resetCount();
+      return { type: 'move', data: motion };
+    }
+
+    if (key === 'j') {
+      const motion = { dr: 1, dc: 0, steps: getCount() };
+      setLastMotion(motion);
+      resetCount();
+      return { type: 'move', data: motion };
+    }
+
+    if (key === 'k') {
+      const motion = { dr: -1, dc: 0, steps: getCount() };
+      setLastMotion(motion);
+      resetCount();
+      return { type: 'move', data: motion };
+    }
+
+    if (key === 'l') {
+      const motion = { dr: 0, dc: 1, steps: getCount() };
+      setLastMotion(motion);
+      resetCount();
+      return { type: 'move', data: motion };
+    }
+
+    if (key === '^') {
+      resetCount();
+      return { type: 'anchor', data: 'start' };
+    }
+
+    if (key === '$') {
+      resetCount();
+      return { type: 'anchor', data: 'end' };
+    }
+
+    if (key === 'g') {
+      resetCount();
+      return { type: 'anchor', data: 'top' };
+    }
+
+    if (key === 'G') {
+      resetCount();
+      return { type: 'anchor', data: 'bottom' };
+    }
+
+    if (key === '.') {
+      const motion = repeatLastMotion();
+      if (motion) {
+        resetCount();
+        return { type: 'repeat', data: motion };
+      }
+    }
+
+    return null;
+  }
+
+  function resetCount(): void {
+    countRef.current = '';
+  }
+
+  function getCount(): number {
+    return Math.max(1, parseInt(countRef.current || '1', 10));
+  }
+
+  function hasCount(): boolean {
+    return countRef.current !== '';
+  }
+
+  function setLastMotion(motion: Motion): void {
+    lastMotionRef.current = motion;
+  }
+
+  function repeatLastMotion(): Motion | null {
+    return lastMotionRef.current;
+  }
+
+  return {
+    processKey,
+    resetCount,
+    getCount,
+    hasCount,
+    setLastMotion,
+    repeatLastMotion
+  };
+}