i18n: extract the settings screens your pass didn't reach (settings)

Part of #145.

`8c9bf0d` localized the settings views themselves; these eight files sit
in the same zone but were not in that pass: the subscription modal, the
child-user creation and password-change modals, both payment result
views, developer settings, and the backup/restore and account-deletion
modals.

Extends the `settings` namespace you established, following its key
naming — 59 keys added to `en/settings.json`. `src/i18n/config.js` is
untouched.

English only — no translations, no behaviour change. Every t() value is
checked against this branch's base: the string must appear
character-for-character in the code it replaces (71 call sites).

One deliberate structural detail: in `BackupRestoreModal` the warning
reads `<strong>Warning:</strong> Restoring a backup will…`. The label and
the sentence are separate keys and the `<strong>` stays in the JSX, so the
emphasis survives and no markup ends up in the dictionary.

If you'd rather keep developer settings hardcoded, say so and I'll drop
that file — it is the one screen here an end user never sees.

src/views/Modals/Inputs/CreateChildUserModal.jsx

@@ -2,8 +2,10 @@ import { FormControl, FormHelperText, Input, Typography } from '@mui/joy'
 import { useEffect, useState } from 'react'
 import ModalActions from '../../../components/common/ModalActions'
 import { useResponsiveModal } from '../../../hooks/useResponsiveModal'
+import { useTranslation } from 'react-i18next'
 
 function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
+  const { t } = useTranslation('settings')
   const { ResponsiveModal } = useResponsiveModal()
 
   const [childName, setChildName] = useState('')
@@ -19,39 +21,38 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
 
     if (touched.childName) {
       if (!childName.trim()) {
-        newErrors.childName = 'Sub account name is required'
+        newErrors.childName = t('childUsers.errNameRequired')
       } else if (childName.length < 2) {
-        newErrors.childName = 'Sub account name must be at least 2 characters'
+        newErrors.childName = t('childUsers.errNameMin')
       } else if (childName.length > 20) {
-        newErrors.childName = 'Sub account name must be less than 20 characters'
+        newErrors.childName = t('childUsers.errNameMax')
       } else if (!/^[a-z.-]+$/.test(childName)) {
-        newErrors.childName =
-          'Sub account name can only contain lowercase letters, dot and dash'
+        newErrors.childName = t('childUsers.errNameChars')
       }
     }
 
     if (touched.password) {
       if (!password) {
-        newErrors.password = 'Password is required'
+        newErrors.password = t('childUsers.errPasswordRequired')
       } else if (password.length < 8) {
-        newErrors.password = 'Password must be between 8 and 64 characters'
+        newErrors.password = t('childUsers.errPasswordLength')
       } else if (password.length > 64) {
-        newErrors.password = 'Password must be between 8 and 64 characters'
+        newErrors.password = t('childUsers.errPasswordLength')
       }
     }
 
     if (touched.confirmPassword) {
       if (password !== confirmPassword) {
-        newErrors.confirmPassword = 'Passwords do not match'
+        newErrors.confirmPassword = t('childUsers.errPasswordMatch')
       }
     }
 
     if (touched.displayName && displayName.length > 50) {
-      newErrors.displayName = 'Display name must be less than 50 characters'
+      newErrors.displayName = t('childUsers.errDisplayNameMax')
     }
 
     setErrors(newErrors)
-  }, [childName, displayName, password, confirmPassword, touched])
+  }, [childName, displayName, password, confirmPassword, touched, t])
 
   const handleSubmit = async () => {
     setTouched({
@@ -101,7 +102,7 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
     <ResponsiveModal
       open={isOpen}
       onClose={handleClose}
-      title='Create Sub Account'
+      title={t('childUsers.createTitle')}
       description='Create a login that can complete tasks assigned to this account.'
       size='md'
       closeOnBackdrop={!isSubmitting}
@@ -109,12 +110,12 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
       footer={
         <ModalActions
           secondary={{
-            label: 'Cancel',
+            label: t('accountSettings.cancel'),
             onClick: handleClose,
             disabled: isSubmitting,
           }}
           primary={{
-            label: 'Create Account',
+            label: t('childUsers.createButton'),
             onClick: handleSubmit,
             disabled: !isValid || isSubmitting,
             loading: isSubmitting,
@@ -124,14 +125,14 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
     >
       <FormControl error={!!errors.childName} sx={{ mb: 2 }}>
         <Typography level='body2' mb={1}>
-          Sub Account Name *
+          {t('childUsers.nameLabel')}
         </Typography>
         <Input
           required
           fullWidth
           id='childName'
           name='childName'
-          placeholder='Enter sub account name (e.g., sarah)'
+          placeholder={t('childUsers.namePlaceholder')}
           value={childName}
           onChange={e => {
             setChildName(e.target.value)
@@ -145,13 +146,13 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
 
       <FormControl error={!!errors.displayName} sx={{ mb: 2 }}>
         <Typography level='body2' mb={1}>
-          Display Name
+          {t('childUsers.displayNameLabel')}
         </Typography>
         <Input
           fullWidth
           id='displayName'
           name='displayName'
-          placeholder='Display name (optional, defaults to sub account name)'
+          placeholder={t('childUsers.displayNamePlaceholder')}
           value={displayName}
           onChange={e => {
             setDisplayName(e.target.value)
@@ -165,7 +166,7 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
 
       <FormControl error={!!errors.password} sx={{ mb: 2 }}>
         <Typography level='body2' mb={1}>
-          Password *
+          {t('childUsers.passwordLabel')}
         </Typography>
         <Input
           required
@@ -173,7 +174,7 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
           name='password'
           type='password'
           id='password'
-          placeholder='Enter password (8-64 characters)'
+          placeholder={t('childUsers.passwordPlaceholder')}
           value={password}
           onChange={e => {
             setPassword(e.target.value)
@@ -185,7 +186,7 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
 
       <FormControl error={!!errors.confirmPassword} sx={{ mb: 3 }}>
         <Typography level='body2' mb={1}>
-          Confirm Password *
+          {t('childUsers.confirmPasswordLabel')}
         </Typography>
         <Input
           required
@@ -193,7 +194,7 @@ function CreateChildUserModal({ isOpen, onClose, onSuccess }) {
           name='confirmPassword'
           type='password'
           id='confirmPassword'
-          placeholder='Confirm password'
+          placeholder={t('childUsers.confirmPasswordPlaceholder')}
           value={confirmPassword}
           onChange={e => {
             setConfirmPassword(e.target.value)