feat: add version history and AI diff highlighting in editor

editor/db/editorDB.ts

@@ -0,0 +1,57 @@
+import Dexie, { type Table } from 'dexie'
+import type { GameData } from '@engine/types'
+
+export interface VersionRecord {
+  id?: number
+  sourcePath: string
+  timestamp: number
+  label: string
+  gameData: GameData
+}
+
+class EditorDB extends Dexie {
+  versions!: Table<VersionRecord, number>
+
+  constructor() {
+    super('EditorVersions')
+    this.version(1).stores({
+      versions: '++id, sourcePath, timestamp',
+    })
+  }
+}
+
+const db = new EditorDB()
+
+export async function putVersion(record: VersionRecord): Promise<void> {
+  try {
+    await db.versions.add(record)
+    const all = await db.versions
+      .where('sourcePath')
+      .equals(record.sourcePath)
+      .reverse()
+      .sortBy('timestamp')
+    if (all.length > 20) {
+      const toDelete = all.slice(20)
+      await db.versions.bulkDelete(toDelete.map((v) => v.id!))
+    }
+  } catch {}
+}
+
+export async function getVersions(sourcePath: string): Promise<VersionRecord[]> {
+  try {
+    return await db.versions
+      .where('sourcePath')
+      .equals(sourcePath)
+      .reverse()
+      .sortBy('timestamp')
+  } catch {
+    return []
+  }
+}
+
+export async function clearVersions(sourcePath: string): Promise<void> {
+  try {
+    const records = await db.versions.where('sourcePath').equals(sourcePath).toArray()
+    await db.versions.bulkDelete(records.map((v) => v.id!))
+  } catch {}
+}