Add safe database migration workflow and note history infrastructure.

This introduces guarded migrations with automatic backups, fixes note creation after DB reset, and wires snapshot/restore history across notes surfaces.

Momento-main/momento/memento-note/lib/note-history.ts

@@ -0,0 +1,121 @@
+import prisma from '@/lib/prisma'
+import { asArray } from '@/lib/utils'
+import type { NoteHistoryEntry } from '@/lib/types'
+
+const HISTORY_TRACKED_FIELDS = [
+  'title',
+  'content',
+  'color',
+  'isPinned',
+  'isArchived',
+  'type',
+  'checkItems',
+  'labels',
+  'images',
+  'links',
+  'isMarkdown',
+  'size',
+  'notebookId',
+] as const
+
+export function shouldCaptureHistorySnapshot(data: Record<string, unknown>): boolean {
+  return HISTORY_TRACKED_FIELDS.some((field) => field in data)
+}
+
+export async function isNoteHistoryEnabledForUser(userId: string): Promise<boolean> {
+  const settings = await prisma.userAISettings.findUnique({
+    where: { userId },
+    select: { noteHistory: true },
+  })
+
+  return settings?.noteHistory === true
+}
+
+export async function createNoteHistorySnapshot({
+  noteId,
+  userId,
+  reason,
+}: {
+  noteId: string
+  userId: string
+  reason?: string
+}): Promise<void> {
+  const note = await prisma.note.findFirst({
+    where: { id: noteId, userId },
+    select: {
+      id: true,
+      userId: true,
+      title: true,
+      content: true,
+      color: true,
+      isPinned: true,
+      isArchived: true,
+      type: true,
+      checkItems: true,
+      labels: true,
+      images: true,
+      links: true,
+      isMarkdown: true,
+      size: true,
+      notebookId: true,
+    },
+  })
+
+  if (!note || !note.userId) return
+
+  await prisma.$transaction(async (tx) => {
+    const lastVersionEntry = await (tx as any).noteHistory.findFirst({
+      where: { noteId },
+      orderBy: { version: 'desc' },
+      select: { version: true },
+    })
+
+    const nextVersion = ((lastVersionEntry?.version as number | undefined) ?? 0) + 1
+
+    await (tx as any).noteHistory.create({
+      data: {
+        noteId: note.id,
+        userId: note.userId,
+        version: nextVersion,
+        reason: reason ?? null,
+        title: note.title,
+        content: note.content,
+        color: note.color,
+        isPinned: note.isPinned,
+        isArchived: note.isArchived,
+        type: note.type,
+        checkItems: note.checkItems,
+        labels: note.labels,
+        images: note.images,
+        links: note.links,
+        isMarkdown: note.isMarkdown,
+        size: note.size,
+        notebookId: note.notebookId,
+      },
+    })
+  })
+}
+
+export function parseNoteHistoryEntry(entry: any): NoteHistoryEntry {
+  return {
+    id: entry.id,
+    noteId: entry.noteId,
+    userId: entry.userId,
+    version: entry.version,
+    reason: entry.reason ?? null,
+    title: entry.title ?? null,
+    content: entry.content,
+    color: entry.color,
+    isPinned: entry.isPinned,
+    isArchived: entry.isArchived,
+    type: entry.type,
+    checkItems: asArray(entry.checkItems, null as any) ?? null,
+    labels: asArray(entry.labels) || null,
+    images: asArray(entry.images) || null,
+    links: asArray(entry.links) || null,
+    isMarkdown: entry.isMarkdown,
+    size: entry.size,
+    notebookId: entry.notebookId ?? null,
+    createdAt: entry.createdAt,
+  }
+}