Fix Task 9: Climb/Descend Controls

1. Fixed exitSpireMode in store.ts to allow exit at any floor for re-entry resume
2. Removed floor restriction on Exit Spire button in page.tsx
3. Updated descend button label to use currentAction for 'Climbing' status

src/app/page.tsx

@@ -273,22 +273,16 @@ export default function ManaLoopGame() {
                     >
                       <ChevronDown className="w-4 h-4 mr-2" />
                       {store.isDescending ? 'Descending…' : 
-                       store.climbDirection === 'up' ? 'Climbing' : 
+                       store.currentAction === 'climb' ? 'Climbing' : 
                        'Begin Descent'}
                     </Button>
-                    {store.currentFloor === 1 ? (
-                      <Button
-                        variant="default"
-                        className="bg-green-600 hover:bg-green-700"
-                        onClick={() => store.exitSpireMode()}
-                      >
-                        Exit Spire
-                      </Button>
-                    ) : (
-                      <span className="text-xs text-gray-400 flex items-center">
-                        Reach floor 1 to exit
-                      </span>
-                    )}
+                    <Button
+                      variant="default"
+                      className="bg-green-600 hover:bg-green-700"
+                      onClick={() => store.exitSpireMode()}
+                    >
+                      Exit Spire
+                    </Button>
                   </div>
                 </div>