feat: Enhance TV support and Daily Weather Forecast (w/ Air Quality)

- **Frontend (Flutter)**
    - Optimize for Google TV: Force Landscape mode, disable touchscreen requirement, and set TV Dashboard as default home.
    - Weather Widget:
        - Add Daily Max/Min temperature ('최고/최저').
        - Add Air Quality Index (AQI) with visual indicator ('미세먼지').
        - Increase font sizes and adjust layout to match Digital Clock style.
        - Implement 1-hour auto-refresh timer.
    - Model: Update WeatherInfo to support tempMin, tempMax, and aqi.

- **Backend (Node.js)**
    - Weather API (/api/weather):
        - Implement daily forecast aggregation logic (Seoul Time KST) to calculate accurate daily High/Low.
        - Integrate OpenWeatherMap Air Pollution API to fetch AQI.

backend/routes/weather.js

@@ -25,9 +25,56 @@ router.get("/", async (req, res) => {
       params.q = q || city;
     }
 
-    const response = await axios.get(`${baseUrl}/weather`, { params });
-    res.json(response.data);
+    // 1. Fetch Current Weather (to get lat/lon and timezone)
+    const currentResponse = await axios.get(`${baseUrl}/weather`, { params });
+    const currentData = currentResponse.data;
+    const { coord } = currentData;
+
+    // 2. Fetch Forecast (for daily min/max) & Air Quality
+    const [forecastResponse, airResponse] = await Promise.all([
+      axios.get(`${baseUrl}/forecast`, {
+        params: { ...params, lat: coord.lat, lon: coord.lon },
+      }),
+      axios.get(`${baseUrl}/air_pollution`, {
+        params: { lat: coord.lat, lon: coord.lon, appid: apiKey },
+      }),
+    ]);
+
+    // 3. Process Forecast for Today's Min/Max (Seoul Time: UTC+9)
+    // OpenWeatherMap returns timestamps in UTC.
+    // Seoul is UTC+9.
+    const SeoulOffset = 9 * 60 * 60 * 1000;
+    const nowKST = new Date(Date.now() + SeoulOffset);
+    const todayStr = nowKST.toISOString().split("T")[0]; // YYYY-MM-DD in KST
+
+    const todayItems = forecastResponse.data.list.filter((item) => {
+      const itemDateKST = new Date(item.dt * 1000 + SeoulOffset);
+      const itemDateStr = itemDateKST.toISOString().split("T")[0];
+      return itemDateStr === todayStr;
+    });
+
+    if (todayItems.length > 0) {
+      // Find min and max from the 3-hour segments
+      const minTemp = Math.min(...todayItems.map((item) => item.main.temp_min));
+      const maxTemp = Math.max(...todayItems.map((item) => item.main.temp_max));
+
+      // Update the response structure
+      currentData.main.temp_min = minTemp;
+      currentData.main.temp_max = maxTemp;
+    }
+
+    // 4. Attach Air Quality (AQI)
+    // OpenWeatherMap AQI: 1 (Good) ... 5 (Very Poor)
+    if (airResponse.data.list && airResponse.data.list.length > 0) {
+      currentData.aqi = airResponse.data.list[0].main.aqi;
+    }
+
+    res.json(currentData);
   } catch (error) {
+    console.error("Weather API Error:", error.message);
+    if (error.response) {
+      console.error("Data:", error.response.data);
+    }
     res.status(500).json({ message: "Failed to fetch weather" });
   }
 });