refactor(scanner): more basic work to get the scanner just running

lstMobile/temps/(tabs)/config.tsx

@@ -0,0 +1,94 @@
+// app/config.tsx
+
+import Constants from "expo-constants";
+import { useRouter } from "expo-router";
+import { useEffect, useState } from "react";
+import { Alert, Button, Text, TextInput, View } from "react-native";
+
+export default function Config() {
+	const [serverUrl, setServerUrl] = useState("");
+	const [scannerId, setScannerId] = useState("");
+	const [config, setConfig] = useState<AppConfig | null>(null);
+	const [loading, setLoading] = useState(true);
+	const router = useRouter();
+
+	const version = Constants.expoConfig?.version;
+	const build = Constants.expoConfig?.android?.versionCode ?? 1;
+
+	useEffect(() => {
+		const loadConfig = async () => {
+			const existing = await getConfig();
+
+			if (existing) {
+				setServerUrl(existing.serverUrl);
+				setScannerId(existing.scannerId);
+				setConfig(existing);
+			}
+
+			setLoading(false);
+		};
+
+		loadConfig();
+	}, []);
+
+	const handleSave = async () => {
+		if (!serverUrl.trim() || !scannerId.trim()) {
+			Alert.alert("Missing info", "Please fill in both fields.");
+			return;
+		}
+
+		await saveConfig({
+			serverUrl: serverUrl.trim(),
+			scannerId: scannerId.trim(),
+		});
+
+		Alert.alert("Saved", "Config saved to device.");
+		//router.replace("/");
+	};
+
+	if (loading) {
+		return <Text>Loading config...</Text>;
+	}
+
+	return (
+		<View style={{ flex: 1, padding: 16, gap: 12 }}>
+			<View style={{ alignItems: "center", margin: 10 }}>
+				<Text style={{ fontSize: 20, fontWeight: "600" }}>
+					LST Scanner Config
+				</Text>
+			</View>
+
+			<Text>Server IP</Text>
+			<TextInput
+				value={serverUrl}
+				onChangeText={setServerUrl}
+				placeholder="192.168.1.1"
+				autoCapitalize="none"
+				keyboardType="numeric"
+				style={{ borderWidth: 1, padding: 10, borderRadius: 8 }}
+			/>
+
+			<Text>Server port</Text>
+			<TextInput
+				value={scannerId}
+				onChangeText={setScannerId}
+				placeholder="3000"
+				autoCapitalize="characters"
+				keyboardType="numeric"
+				style={{ borderWidth: 1, padding: 10, borderRadius: 8 }}
+			/>
+
+			<View
+				style={{ flexDirection: "row", justifyContent: "center", padding: 3 }}
+			>
+				<Button title="Save Config" onPress={handleSave} />
+			</View>
+
+			<View style={{ marginTop: "auto", alignItems: "center", padding: 10 }}>
+				<Text style={{ fontSize: 12, color: "#666" }}>
+					LST Scanner v{version}-{build}
+				</Text>
+			</View>
+		</View>
+	);
+}