Localize remaining hardcoded UI strings and persist language preference

Replaces the last hardcoded English strings (initial-scene modals, game
menu save status messages) with locale-loaded text, adds a shared
LOCALE_LIST so the settings dropdown and locale manager stay in sync,
and persists the chosen language into savemeta_t across all platforms.
Also fixes two message buffers that were too small for their longest
translations.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

assets/locale/en_US.po

@@ -60,6 +60,58 @@ msgstr "Settings"
 msgid "ui.game_menu.save"
 msgstr "Save"
 
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_success"
+msgstr "Game saved."
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_cancelled"
+msgstr "Save cancelled."
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_unavailable"
+msgstr "Can't save - no save device found."
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_temporary"
+msgstr "This session is temporary - no save device was found, so saving is disabled."
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_create_confirm"
+msgstr "No save data found. Create a new save?"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_failed_format"
+msgstr "Save failed: %s"
+
+#: src/dusk/ui/frame/game/uigamemenu.c
+msgid "ui.game_menu.save_check_failed_format"
+msgstr "Can't save: %s"
+
+#: src/dusk/ui/frame/initial/uiinitialnocard.c
+msgid "ui.initial.no_card.message"
+msgstr "No save device found. You can continue, but\nprogress will not be saved."
+
+#: src/dusk/ui/frame/initial/uiinitialnocard.c
+msgid "ui.initial.no_card.retry"
+msgstr "Retry"
+
+#: src/dusk/ui/frame/initial/uiinitialnocard.c
+msgid "ui.initial.no_card.continue"
+msgstr "Continue Anyway"
+
+#: src/dusk/ui/frame/initial/uiinitialcreatesave.c
+msgid "ui.initial.create_save.message"
+msgstr "No save data found. Create a new save?"
+
+#: src/dusk/ui/frame/initial/uiinitialcreatesave.c
+msgid "ui.initial.create_save.yes"
+msgstr "Yes"
+
+#: src/dusk/ui/frame/initial/uiinitialcreatesave.c
+msgid "ui.initial.create_save.no"
+msgstr "No"
+
 msgid "item.potion.name"
 msgstr "Potion"