fix(settings): the pairing code can be read by the phone's camera

The phone app now opens from its tty7pair: link, so Show code says to
point the phone's camera at it first.

src/ui/i18n/en.rs

@@ -63,7 +63,7 @@ pub fn translate_en(key: L10nKey) -> &'static str {
         L10nKey::SettingsMobilePairDesc => "Shows a one-time code for the tty7 app on your phone.",
         L10nKey::SettingsMobilePairNeedsAccess => "Turn on phone access first.",
         L10nKey::SettingsMobilePairScan => {
-            "Scan this with the tty7 app on your phone, or copy the code and paste it there."
+            "Point your phone's camera at this, or scan it in the tty7 app, or copy the code and paste it there."
         }
         L10nKey::SettingsMobilePairValid => "Expires in {time}. Works for one phone.",
         L10nKey::SettingsMobileNewCode => "New code",

src/ui/i18n/ja.rs

@@ -71,7 +71,7 @@ pub fn translate_ja(key: L10nKey) -> Option<&'static str> {
             "先にスマートフォンからのアクセスをオンにしてください。"
         }
         L10nKey::SettingsMobilePairScan => {
-            "スマートフォンの tty7 アプリでスキャンするか、コードをコピーして貼り付けてください。"
+            "スマートフォンのカメラを向けるか、tty7 アプリでスキャンするか、コードをコピーして貼り付けてください。"
         }
         L10nKey::SettingsMobilePairValid => {
             "あと {time} で失効します。1 台のスマートフォンに限ります。"

src/ui/i18n/zh.rs

@@ -58,7 +58,9 @@ pub fn translate_zh(key: L10nKey) -> Option<&'static str> {
         L10nKey::SettingsMobileShowCode => "显示配对码",
         L10nKey::SettingsMobilePairDesc => "生成一个一次性配对码，给手机上的 tty7 app 用。",
         L10nKey::SettingsMobilePairNeedsAccess => "请先打开手机访问。",
-        L10nKey::SettingsMobilePairScan => "用手机上的 tty7 app 扫描，或者复制配对码粘贴过去。",
+        L10nKey::SettingsMobilePairScan => {
+            "用手机相机对准它，或在 tty7 app 里扫描，或者复制配对码粘贴过去。"
+        }
         L10nKey::SettingsMobilePairValid => "{time} 后失效，只能配对一台手机。",
         L10nKey::SettingsMobileNewCode => "换一个配对码",
         L10nKey::SettingsMobilePairExpired => "这个配对码已过期。生成一个新的再配对。",