Add storage-backed story history

src/engine/ink-engine.ts

@@ -109,12 +109,27 @@ export class InkEngine {
     if (!this.story) {
       throw new Error('No active Ink story to save');
     }
-    return this.story.state.toJson();
+    return JSON.stringify({
+      inkState: this.story.state.toJson(),
+      nextTurnId: this.nextTurnId,
+    });
   }
 
   loadGame(savedState: string): TurnResult {
     this.story = this.loadStory();
-    this.story.state.LoadJson(savedState);
+    let inkState = savedState;
+    try {
+      const parsed = JSON.parse(savedState);
+      if (parsed && typeof parsed.inkState === 'string') {
+        inkState = parsed.inkState;
+        if (Number.isInteger(parsed.nextTurnId)) {
+          this.nextTurnId = Math.max(1, parsed.nextTurnId);
+        }
+      }
+    } catch {
+      // Backward compatibility with raw Ink state JSON.
+    }
+    this.story.state.LoadJson(inkState);
     return this.continueStory();
   }
 

src/server-ink.ts

@@ -130,11 +130,12 @@ async function handleGameApi(
     case 'loadGame':
     case 'loadGame()': {
       const slot = normalizeSaveSlot(args[0]);
-      if (!slots.has(slot)) {
+      const browserSave = typeof args[1] === 'string' ? args[1] : null;
+      if (!browserSave && !slots.has(slot)) {
         return { success: false, error: 'missing_save', result: false };
       }
       const engine = getOrCreateEngine(socket.id);
-      socket.emit('narrativeResponse', engine.loadGame(slots.get(slot)!));
+      socket.emit('narrativeResponse', engine.loadGame(browserSave || slots.get(slot)!));
       socket.emit('gameLoaded', { slot });
       return { success: true, result: true, running: true, slot };
     }
@@ -146,9 +147,10 @@ async function handleGameApi(
         return { success: false, error: 'game_not_running', result: false };
       }
       const slot = normalizeSaveSlot(args[0]);
-      slots.set(slot, engine.saveGame());
+      const savedState = engine.saveGame();
+      slots.set(slot, savedState);
       socket.emit('gameSaved', { slot });
-      return { success: true, result: true, slot };
+      return { success: true, result: true, slot, savedState };
     }
 
     case 'hasSaveGame':