feat(web): add player name, freeform input, and unified settings modal

- Player name: stored in localStorage, injected into Architect/Writer/InsertBeat
  prompts so NPCs address the player by name, displayed in dialogue UI
- Freeform input: compact button at choice nodes expands to text input, LLM
  classifier routes to insert-beat (interactive NPC response) or change-scene
- SettingsModal: unified panel merging player name, voice toggle (with
  collapsible TTS key section), replacing the old TtsKeyModal
- Insert-beat upgrade: prompt now requires NPC reaction when characters are
  present, shared by both freeform and Vision paths
- IME guard: isComposing check on freeform input to prevent CJK mid-composition
  submission

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

components/DialogueHistoryModal.tsx

@@ -16,11 +16,15 @@ export function DialogueHistoryModal({
   items,
   portrait,
   onClose,
+  playerName,
 }: {
   items: DialogueHistoryItem[];
   portrait: boolean;
   onClose: () => void;
+  playerName?: string;
 }) {
+  const displaySpeaker = (s: string | undefined) =>
+    s === "你" && playerName ? playerName : s;
   const listRef = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
@@ -97,7 +101,7 @@ export function DialogueHistoryModal({
                     </span>
                     {item.speaker && (
                       <span className="font-serif text-[12px] text-[rgba(205,165,90,0.92)]">
-                        {item.speaker}
+                        {displaySpeaker(item.speaker)}
                       </span>
                     )}
                   </div>