feat(know-your-world): make magnifier lazy - only move when cursor obscured

The magnifier now stays in place unless the cursor enters its bounds.
This reduces visual distraction since the magnifier won't constantly
jump to opposite corners as the user moves the mouse.

- Track current magnifier bounds (position + dimensions)
- Check if cursor is within magnifier area (with 10px padding)
- Only calculate new position when cursor would be obscured
- Otherwise keep magnifier at its current position

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/web/src/arcade-games/know-your-world/components/MapRenderer.tsx

@@ -1588,20 +1588,40 @@ export function MapRenderer({
       const magnifierWidth = containerRect.width * MAGNIFIER_SIZE_RATIO
       const magnifierHeight = containerRect.height * MAGNIFIER_SIZE_RATIO
 
-      // Calculate magnifier position (opposite corner from cursor)
-      // magnifierWidth and magnifierHeight already declared above
-      const isLeftHalf = cursorX < containerRect.width / 2
-      const isTopHalf = cursorY < containerRect.height / 2
+      // Lazy magnifier positioning: only move if cursor would be obscured
+      // Check if cursor is within current magnifier bounds (with padding)
+      const padding = 10 // pixels of buffer around magnifier
+      const currentMagLeft = targetLeft
+      const currentMagTop = targetTop
+      const currentMagRight = currentMagLeft + magnifierWidth
+      const currentMagBottom = currentMagTop + magnifierHeight
 
-      const newTop = isTopHalf ? containerRect.height - magnifierHeight - 20 : 20
-      const newLeft = isLeftHalf ? containerRect.width - magnifierWidth - 20 : 20
+      const cursorInMagnifier =
+        cursorX >= currentMagLeft - padding &&
+        cursorX <= currentMagRight + padding &&
+        cursorY >= currentMagTop - padding &&
+        cursorY <= currentMagBottom + padding
+
+      // Only calculate new position if cursor would be obscured
+      let newTop = targetTop
+      let newLeft = targetLeft
+
+      if (cursorInMagnifier) {
+        // Move to opposite corner from cursor
+        const isLeftHalf = cursorX < containerRect.width / 2
+        const isTopHalf = cursorY < containerRect.height / 2
+
+        newTop = isTopHalf ? containerRect.height - magnifierHeight - 20 : 20
+        newLeft = isLeftHalf ? containerRect.width - magnifierWidth - 20 : 20
+      }
 
       if (pointerLocked) {
         console.log(
           '[Magnifier] SHOWING with zoom:',
           adaptiveZoom,
           '| Setting opacity to 1, position:',
-          { top: newTop, left: newLeft }
+          { top: newTop, left: newLeft },
+          cursorInMagnifier ? '(moved - cursor was in magnifier)' : '(staying put)'
         )
       }