refactor(settings): split SettingsScreen into section components and pure helpers

SettingsScreen CC 23 -> below 10. Form parsing, change detection and the dark-theme check moved to utils/ with unit tests; the dark switch now reads the OS scheme instead of comparing the background colour. Adds characterization tests for the screen.

components/settings/AboutCard.tsx

@@ -0,0 +1,38 @@
+import { useThemeColor } from '@/hooks/useThemeColor';
+import { Info, MonitorCog } from 'lucide-react-native';
+import React from 'react';
+import { StyleSheet, Text, View } from 'react-native';
+import { SettingsSection } from './SettingsSection';
+
+export function AboutCard() {
+    const colors = useThemeColor();
+
+    return (
+        <SettingsSection title="ABOUT">
+            <View style={styles.rowGroup}>
+                <Info size={18} color={colors.textMuted} style={styles.infoIcon} />
+                <Text style={[styles.infoText, { color: colors.text }]}>LocalMind - Cross Platform Version</Text>
+            </View>
+            <View style={[styles.rowGroup, { marginTop: 8 }]}>
+                <MonitorCog size={18} color={colors.textMuted} style={styles.infoIcon} />
+                <Text style={[styles.infoText, { color: colors.textMuted, fontSize: 13 }]}>
+                    Connected via OpenAPI `/v1/chat/completions` specs
+                </Text>
+            </View>
+        </SettingsSection>
+    );
+}
+
+const styles = StyleSheet.create({
+    rowGroup: {
+        flexDirection: 'row',
+        alignItems: 'center',
+    },
+    infoIcon: {
+        marginRight: 10,
+    },
+    infoText: {
+        fontSize: 15,
+        lineHeight: 22,
+    },
+});