Fix getters mutating state on repeated access

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

tests/stores/allMapData.test.js

@@ -237,5 +237,28 @@ describe('allMapDataStore', () => {
       store.allBaseCase = [{ id: 1 }];
       expect(store.BaseInfiniteFirstCases).toBeUndefined();
     });
+
+    it('filterAttrs getter does not corrupt original state on repeated access', () => {
+      const originalDate = '2023-06-15T10:30:00Z';
+      store.allFilterAttrs = [
+        { type: 'date', min: originalDate, max: '2023-12-31T23:59:00Z' },
+      ];
+      // Access the getter once
+      store.filterAttrs;
+      // The original state should still contain the ISO date, not a formatted string
+      expect(store.allFilterAttrs[0].min).toBe(originalDate);
+    });
+
+    it('filterAttrs getter returns consistent float values on repeated access', () => {
+      store.allFilterAttrs = [
+        { type: 'float', min: 1.239, max: 5.671 },
+      ];
+      const first = store.filterAttrs;
+      const second = store.filterAttrs;
+      // min rounds down (ROUND_DOWN=1), max rounds up (ROUND_UP=0)
+      // Both accesses should produce the same result
+      expect(first[0].min).toBe(second[0].min);
+      expect(first[0].max).toBe(second[0].max);
+    });
   });
 });