i18n: localize hardcoded UI strings across 10 components

Wraps the hardcoded strings flagged in LOTUS_BUGS.md (Localization rows)
in t() via react-i18next, and adds the keys to public/locales/en.json
under the existing Organisms.* namespace. de.json intentionally left to
fall back to en for now (fallbackLng: 'en') rather than fabricate
translations.

Files: CreateRoomTypeSelector, ImageViewer, MsgTypeRenderers (MLocation),
Reply (ThreadIndicator), ImageContent, DeviceVerification (5 subcomponents),
UrlPreviewCard (DiscordCard), InviteUserPrompt, UploadBoard, PasswordStage.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/locales/en.json

@@ -2,6 +2,46 @@
   "Organisms": {
     "RoomCommon": {
       "changed_room_name": " changed room name"
+    },
+    "CreateRoom": {
+      "chat_room": "Chat Room",
+      "chat_room_desc": "Messages, photos, and videos.",
+      "voice_room": "Voice Room",
+      "voice_room_desc": "Live audio and video conversations."
+    },
+    "ImageViewer": {
+      "download": "Download"
+    },
+    "Message": {
+      "open_location": "Open Location",
+      "thread": "Thread"
+    },
+    "ImageContent": {
+      "view": "View",
+      "spoiler": "Spoiler",
+      "retry": "Retry"
+    },
+    "DeviceVerification": {
+      "close": "Close",
+      "accept": "Accept",
+      "they_match": "They Match",
+      "okay": "Okay"
+    },
+    "UrlPreview": {
+      "join_server": "Join Server"
+    },
+    "InviteUser": {
+      "invite": "Invite"
+    },
+    "UploadBoard": {
+      "files": "Files",
+      "send": "Send",
+      "upload_failed": "Upload Failed"
+    },
+    "PasswordStage": {
+      "account_password": "Account Password",
+      "password": "Password",
+      "invalid_password": "Invalid Password!"
     }
   }
 }