feat(lstmobile): intial scanner setup kinda working

lstMobile/src/app/(tabs)/config.tsx

@@ -0,0 +1,92 @@
+// app/config.tsx
+import { useEffect, useState } from "react";
+import { View, Text, TextInput, Button, Alert } from "react-native";
+import { useRouter } from "expo-router";
+import { AppConfig, getConfig, saveConfig } from "../../lib/storage";
+import Constants from "expo-constants";
+
+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>
+  );
+}