Fix Live Activity lock screen rendering and polish multi-account auth.

Flatten widget layouts and use system colors so banner and expanded regions render on vibrant lock screens; migrate auth sessions per account to prevent double sign-in; scope app lock PIN to accounts; default clock description to "Clock In"; add architecture docs and deferred form validation on auth screens.

Co-authored-by: Cursor <cursoragent@cursor.com>

components/ui/SelectField.tsx

@@ -23,6 +23,8 @@ type SelectFieldProps = {
   value: string;
   options: SelectOption[];
   disabled?: boolean;
+  required?: boolean;
+  error?: string;
   onValueChange: (value: string) => void;
 };
 
@@ -32,6 +34,8 @@ export function SelectField({
   value,
   options,
   disabled,
+  required,
+  error,
   onValueChange,
 }: SelectFieldProps) {
   const { colors } = useAppTheme();
@@ -40,7 +44,10 @@ export function SelectField({
 
   return (
     <View style={styles.wrapper}>
-      <Text style={[styles.label, { color: colors.foreground }]}>{label}</Text>
+      <Text style={[styles.label, { color: colors.foreground }]}>
+        {label}
+        {required ? <Text style={{ color: colors.destructive }}> *</Text> : null}
+      </Text>
       <Pressable
         accessibilityRole="button"
         disabled={disabled}
@@ -48,7 +55,7 @@ export function SelectField({
         style={({ pressed }) => [
           styles.trigger,
           {
-            borderColor: colors.borderGlass,
+            borderColor: error ? colors.destructive : colors.borderGlass,
             backgroundColor: colors.cardGlass,
           },
           disabled && styles.triggerDisabled,
@@ -122,6 +129,9 @@ export function SelectField({
           </Pressable>
         </Pressable>
       </Modal>
+      {error ? (
+        <Text style={[styles.error, { color: colors.destructive }]}>{error}</Text>
+      ) : null}
     </View>
   );
 }
@@ -134,6 +144,10 @@ const styles = StyleSheet.create({
     fontSize: 14,
     fontFamily: fonts.bodyMedium,
   },
+  error: {
+    fontSize: 13,
+    fontFamily: fonts.body,
+  },
   trigger: {
     minHeight: 44,
     borderWidth: 1,