refactor: use CustomTextInput in login and register screens

- Replace raw TextInput with CustomTextInput in login and register
  for consistent focus border effect across the app
- Add placeholder, secureTextEntry, autoCapitalize, keyboardType
  props to CustomTextInput
- Remove hardcoded default padding (px-3 py-2) and h-11/12 from
  CustomTextInput, callers now set padding via className
- Add explicit px-3 py-2 to existing callers (settings, editEvent)
- Update CLAUDE.md with new CustomTextInput usage and props

apps/client/src/components/CustomTextInput.tsx

@@ -1,4 +1,4 @@
-import { TextInput } from "react-native";
+import { TextInput, TextInputProps } from "react-native";
 import { useThemeStore } from "../stores/ThemeStore";
 import { useState } from "react";
 
@@ -8,6 +8,11 @@ export type CustomTextInputProps = {
   className?: string;
   multiline?: boolean;
   onValueChange?: (text: string) => void;
+  placeholder?: string;
+  placeholderTextColor?: string;
+  secureTextEntry?: boolean;
+  autoCapitalize?: TextInputProps["autoCapitalize"];
+  keyboardType?: TextInputProps["keyboardType"];
 };
 
 const CustomTextInput = (props: CustomTextInputProps) => {
@@ -16,10 +21,15 @@ const CustomTextInput = (props: CustomTextInputProps) => {
 
   return (
     <TextInput
-      className={`border border-solid rounded-2xl px-3 py-2 h-11/12 ${props.className}`}
+      className={`border border-solid rounded-2xl ${props.className}`}
       onChangeText={props.onValueChange}
       value={props.text}
       multiline={props.multiline}
+      placeholder={props.placeholder}
+      placeholderTextColor={props.placeholderTextColor}
+      secureTextEntry={props.secureTextEntry}
+      autoCapitalize={props.autoCapitalize}
+      keyboardType={props.keyboardType}
       style={{
         backgroundColor: theme.messageBorderBg,
         color: theme.textPrimary,