Add Wi-Fi scan details display and MQTT publish

- HTML: Add Wi-Fi scan results container to network.html
- Rust: Implement `wifi_scan_details()` with RSSI, channel, auth method
- API & UI: Fetch and display scan results in table format
- MQTT: Publish top 10 networks sorted by RSSI to `/wifi_scan`

Software/MainBoard/rust/src_webpack/src/api.ts

@@ -225,6 +225,15 @@ export interface Detection {
     plant: DetectionPlant[]
 }
 
+/// Wi-Fi scan result details for UI display
+export interface WifiScanResult {
+    ssid: string,
+    bssid: string,
+    rssi: number, // signal strength in dBm
+    channel: number,
+    auth_method: string
+}
+
 export interface TankInfo {
     /// there is enough water in the tank
     enough_water: boolean,