feat(applock): blinking PIN cursor + misc UI polish (#4110)

* feat(applock): show blinking cursor on PIN input

Empty PIN slots used to render nothing, leaving no cue for which
position is active. Add a thin underscore that blinks under the
next-to-fill slot while the input is focused.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* chore(ui): misc settings polish + i18n refresh

- applock screen: switch fixed positioning to full-height so the lock
  screen sits inside the safe area
- applock dialog: split the recovery sentence so it reads cleanly
  without an em dash
- settings: rename "Interface Language" to "Language"
- translators: drop the "(Unavailable)" suffix from disabled providers;
  the row already greys out
- ruler color picker: keep swatches clickable when ruler is off so
  users can still set a color before enabling
- refresh translations across all locales for the changed strings

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/readest-app/src/components/settings/AppLockDialog.tsx

@@ -183,7 +183,7 @@ export default function AppLockDialog() {
   const description =
     mode === 'set'
       ? _(
-          'Pick a 4-digit PIN. You will need to enter it every time you open Readest. There is no way to recover a forgotten PIN — clearing the app data is the only way to reset it.',
+          'Pick a 4-digit PIN. You will need to enter it every time you open Readest. There is no way to recover a forgotten PIN. Clearing the app data is the only way to reset it.',
         )
       : mode === 'change'
         ? _('Enter your current PIN, then choose a new 4-digit PIN.')

apps/readest-app/src/components/settings/LangPanel.tsx

@@ -273,7 +273,7 @@ const LangPanel: React.FC<SettingsPanelPanelProp> = ({ bookKey, onRegisterReset
         <div className='card border-base-200 bg-base-100 border shadow'>
           <div className='divide-base-200 divide-y'>
             <div className='config-item'>
-              <span className=''>{_('Interface Language')}</span>
+              <span className=''>{_('Language')}</span>
               <Select
                 value={getCurrentUILangOption().value}
                 onChange={handleSelectUILang}

apps/readest-app/src/components/settings/color/ReadingRulerSettings.tsx

@@ -63,11 +63,11 @@ const ReadingRulerSettings: React.FC<ReadingRulerSettingsProps> = ({
               {RULER_COLORS.map(({ value, className, hoverClassName }) => (
                 <button
                   key={value}
-                  disabled={!enabled}
+                  // disabled={!enabled}
                   className={`btn btn-circle btn-sm ${className} ${hoverClassName} ${
                     color === value ? 'ring-base-content ring-2 ring-offset-1' : ''
-                  } ${!enabled ? 'btn-disabled opacity-50' : ''}`}
-                  onClick={() => onColorChange(value)}
+                  } ${!enabled ? 'opacity-50' : ''}`}
+                  onClick={() => enabled && onColorChange(value)}
                 />
               ))}
             </div>