feat(voice): add typed AI chat beside voice

Chat sits next to the mic in the command dock. Replies are silent and never
request the microphone; the first message connects with the selected provider
and runs the same map actions as voice through each provider's text API
(OpenAI OPENAI_CHAT_MODEL, Gemini GEMINI_CHAT_MODEL via generateContent, which
never starts Live). Only one mode runs at a time.

- Chat panel rendered by the voice control presenter: conversation, recent and
  quick-command suggestions, Up/Down history, attachments (map-layer
  references or small UTF-8 text files, sent only with the message)
- Chat and voice panels sit above the dock or dock into the right rail's
  column; minimized bars sit centred above the dock, and height animates on
  swaps
- A centred panel steps down to its bar for the Location and Visual Presets
  trays without moving focus, rests above an open tray, and docks right while
  expanded over one; it returns to the centre once the trays close
- Minimized voice previews the last sentence from each side; the empty Voice
  Preview suggests things to say
- Settings opened from chat keep chat's frame and show the shared AI provider
  and quick commands; voice Settings show Back to voice
- Closing chat ends a typed session; the voice panel's close turns voice off
- The dock widens its voice control for the chat button and restyles its
  wings, which show icons only at 900px and below; assistant panels share the
  left panels' glass, and Cyber keeps its own surfaces
- Server text-chat handlers with body, time and per-IP limits
  (GEV_RATELIMIT_*_CHAT_PER_MIN), documented in SECURITY.md; tests and all
  eleven locales

Co-authored-by: Darren Dignam <[email protected]>

src/i18n/locales/ja.json

@@ -2868,5 +2868,67 @@
   "Left panels": "左パネル",
   "Right panels": "右パネル",
   "CONFIRMED": "確認済み",
-  "PAD / RTLS": "射場 / RTLS"
+  "PAD / RTLS": "射場 / RTLS",
+  "Fly to Tokyo": "東京へ移動",
+  "Show live flights": "ライブのフライトを表示",
+  "AI chat": "AIチャット",
+  "GEV CHAT": "GEV チャット",
+  "Ask about the map. Tell it where to go.": "地図について質問できます。行き先を伝えてください。",
+  "Close chat": "チャットを閉じる",
+  "Conversation": "会話",
+  "Explore with a question": "質問から探索",
+  "Find a place, explore live data, or change your view.": "場所を探したり、ライブデータを見たり、表示を変えたりできます。",
+  "Attachments": "添付ファイル",
+  "Remove attachment": "添付を削除",
+  "Attach a map layer": "地図レイヤーを添付",
+  "Choose a layer…": "レイヤーを選択…",
+  "Attach a file": "ファイルを添付",
+  "TXT, Markdown, CSV, JSON or GeoJSON · up to 10 KB each. Attachments are sent to your AI provider with your message.": "TXT、Markdown、CSV、JSON、GeoJSON · 各 10 KB まで。添付はメッセージとともに AI プロバイダーへ送信されます。",
+  "Latest AI response": "最新の AI の応答",
+  "Expand conversation": "会話を展開",
+  "Command suggestions": "コマンドの候補",
+  "Expand chat": "チャットを展開",
+  "Add attachment": "添付を追加",
+  "Message GEV": "GEV へのメッセージ",
+  "Ask GEV anything about the map…": "地図について GEV に何でも質問…",
+  "Stop reply": "応答を停止",
+  "Send message": "メッセージを送信",
+  "Panel position": "パネルの位置",
+  "Move above the dock": "ドックの上へ移動",
+  "Dock to the right": "右側にドッキング",
+  "Expand panel": "パネルを展開",
+  "Minimize panel": "パネルを最小化",
+  "You can attach up to four items.": "添付できるのは 4 件までです。",
+  "Attachments are too large together. Use smaller files.": "添付ファイルの合計が大きすぎます。小さいファイルを使ってください。",
+  "Choose a TXT, Markdown, CSV, JSON or GeoJSON file.": "TXT、Markdown、CSV、JSON、GeoJSON のファイルを選んでください。",
+  "Each file must be 10 KB or smaller.": "各ファイルは 10 KB 以下にしてください。",
+  "Choose a non-empty UTF-8 text file.": "空でない UTF-8 のテキストファイルを選んでください。",
+  "Connecting…": "接続中…",
+  "Thinking…": "考え中…",
+  "Working on the map…": "地図を操作中…",
+  "Silent chat · microphone off": "サイレントチャット · マイクオフ",
+  "Reply interrupted. You can try again.": "応答が中断されました。もう一度お試しください。",
+  "Could not connect. Try again.": "接続できませんでした。もう一度お試しください。",
+  "Session ended. Send a message to start a new conversation.": "セッションが終了しました。メッセージを送ると新しい会話を始められます。",
+  "Connection timed out. Try again.": "接続がタイムアウトしました。もう一度お試しください。",
+  "Chat closed.": "チャットを閉じました。",
+  "Connection stopped.": "接続が停止しました。",
+  "Message and attachments are too large. Remove an attachment or shorten your message.": "メッセージと添付が大きすぎます。添付を外すか、メッセージを短くしてください。",
+  "Message was not sent. Try again.": "メッセージを送信できませんでした。もう一度お試しください。",
+  "Reply stopped.": "応答を停止しました。",
+  "Suggestions": "候補",
+  "Recent": "最近",
+  "Quick commands": "クイックコマンド",
+  "Open AI chat": "AIチャットを開く",
+  "CHAT": "チャット",
+  "Back to chat": "チャットに戻る",
+  "Back to voice": "音声に戻る",
+  "Latest voice exchange": "直近の音声のやり取り",
+  "Try saying": "話しかけてみましょう",
+  "What am I looking at?": "何を見ていますか？",
+  "AI Provider": "AI プロバイダー",
+  "The selected AI provider is shared by voice and chat.": "選んだ AI プロバイダーは音声とチャットで共通です。",
+  "Show quick commands": "クイックコマンドを表示",
+  "Chat replies are silent. No microphone access is needed.": "チャットの応答は音声なしです。マイクへのアクセスは不要です。",
+  "Chat": "チャット"
 }