fix: change dev port from 9700 to 9710 (avoid BridgeCoach conflict)

Port 9700 was occupied by BridgeCoach Docker container, causing the
Tauri debug binary to load the wrong frontend. Changed to 9710:
- vite.config.ts: server.port 9700 → 9710
- tauri.conf.json: devUrl localhost:9700 → localhost:9710
- wdio.conf.js: DEV_URL_PORT check updated
- Binary rebuilt with new port baked in

vite.config.ts

@@ -4,7 +4,7 @@ import { svelte } from '@sveltejs/vite-plugin-svelte'
 export default defineConfig({
   plugins: [svelte()],
   server: {
-    port: 9700,
+    port: 9710,
     strictPort: true,
   },
   clearScreen: false,