fix: validate saved plan confidence

apps/web/tests/plan-page.spec.ts

@@ -67,6 +67,11 @@ test("plan preserves a real zero confidence and bounds imported text", async ({
     method: "Спиннинг",
     retrieve: "равномерная",
     oversized: "x".repeat(5000),
+  }, {
+    key: "/spots/vyunok-7450x7451",
+    waterbody: "Вьюнок",
+    coordinates: "7450:7451",
+    confidence: "999",
   }])));
   await page.reload();
 
@@ -74,6 +79,7 @@ test("plan preserves a real zero confidence and bounds imported text", async ({
   const stored = await page.evaluate(() => JSON.parse(localStorage.getItem("rf4spotter:fishing-plan") || "[]"));
   expect(stored[0].key.length).toBeLessThanOrEqual(512);
   expect(stored[0].confidence).toBe("0");
+  expect(stored[1].confidence).toBe("");
   expect(stored[0].oversized).toBeUndefined();
 });