feat(backend): update collections, config and migration tools

Update Payload CMS configuration, collections (Audit, Posts), and add migration scripts/reports.

apps/backend/scripts/migration/reporter.ts

@@ -0,0 +1,188 @@
+/**
+ * Migration Reporter
+ * Story 1.3: Content Migration Script
+ *
+ * Generates migration reports in JSON and Markdown formats
+ */
+
+import type { MigrationReport, CollectionMigrationResult } from './types'
+import { writeFile, mkdir } from 'fs/promises'
+import { join } from 'path'
+import { existsSync } from 'fs'
+
+// ============================================================
+// REPORT GENERATION
+// ============================================================
+
+/**
+ * Create a new empty report
+ */
+export function createReport(dryRun: boolean = false): MigrationReport {
+  return {
+    timestamp: new Date().toISOString(),
+    dryRun,
+    summary: {
+      total: 0,
+      created: 0,
+      skipped: 0,
+      failed: 0,
+    },
+    byCollection: {},
+    details: {},
+  }
+}
+
+/**
+ * Update report with collection results
+ */
+export function updateReport(
+  report: MigrationReport,
+  collectionResult: CollectionMigrationResult,
+): MigrationReport {
+  const { collection, created, skipped, failed } = collectionResult
+
+  // Update byCollection stats
+  report.byCollection[collection] = { created, skipped, failed }
+
+  // Store details
+  report.details[collection] = collectionResult
+
+  // Update summary
+  report.summary.total += created + skipped + failed
+  report.summary.created += created
+  report.summary.skipped += skipped
+  report.summary.failed += failed
+
+  return report
+}
+
+/**
+ * Generate markdown report
+ */
+export function generateMarkdownReport(report: MigrationReport): string {
+  const lines: string[] = []
+
+  lines.push(`# Migration Report`)
+  lines.push(``)
+  lines.push(`**Generated:** ${new Date(report.timestamp).toLocaleString('zh-TW')}`)
+  lines.push(`**Mode:** ${report.dryRun ? '🧪 Dry Run (no changes made)' : '✅ Live Migration'}`)
+  lines.push(``)
+  lines.push(`---`)
+  lines.push(``)
+
+  // Summary section
+  lines.push(`## Summary`)
+  lines.push(``)
+  lines.push(`| Metric | Count |`)
+  lines.push(`|--------|-------|`)
+  lines.push(`| Total Items | ${report.summary.total} |`)
+  lines.push(`| ✅ Created | ${report.summary.created} |`)
+  lines.push(`| ⏭️ Skipped | ${report.summary.skipped} |`)
+  lines.push(`| ❌ Failed | ${report.summary.failed} |`)
+  lines.push(``)
+
+  // By collection section
+  lines.push(`## By Collection`)
+  lines.push(``)
+
+  for (const [collection, stats] of Object.entries(report.byCollection)) {
+    lines.push(`### ${collection.charAt(0).toUpperCase() + collection.slice(1)}`)
+    lines.push(``)
+    lines.push(`| Metric | Count |`)
+    lines.push(`|--------|-------|`)
+    lines.push(`| Created | ${stats.created} |`)
+    lines.push(`| Skipped | ${stats.skipped} |`)
+    lines.push(`| Failed | ${stats.failed} |`)
+    lines.push(``)
+  }
+
+  // Details section
+  if (report.details) {
+    lines.push(`## Details`)
+    lines.push(``)
+
+    for (const [collection, result] of Object.entries(report.details)) {
+      lines.push(`### ${collection.charAt(0).toUpperCase() + collection.slice(1)}`)
+      lines.push(``)
+
+      // Created items
+      if (result.results.some((r) => r.success)) {
+        lines.push(`#### ✅ Created (${result.results.filter((r) => r.success).length})`)
+        lines.push(``)
+        for (const item of result.results.filter((r) => r.success)) {
+          lines.push(`- \`${item.slug}\` (ID: ${item.id})`)
+        }
+        lines.push(``)
+      }
+
+      // Failed items
+      if (result.results.some((r) => !r.success)) {
+        lines.push(`#### ❌ Failed (${result.results.filter((r) => !r.success).length})`)
+        lines.push(``)
+        for (const item of result.results.filter((r) => !r.success)) {
+          lines.push(`- \`${item.slug}\`: ${item.error}`)
+        }
+        lines.push(``)
+      }
+    }
+  }
+
+  return lines.join('\n')
+}
+
+/**
+ * Save report to files
+ */
+export async function saveReport(
+  report: MigrationReport,
+  outputDir: string = './reports',
+): Promise<void> {
+  // Ensure directory exists
+  if (!existsSync(outputDir)) {
+    await mkdir(outputDir, { recursive: true })
+  }
+
+  const timestamp = new Date().toISOString().replace(/[:.]/g, '-').split('T')[0]
+  const baseName = `migration-${timestamp}`
+
+  // Save JSON report
+  const jsonPath = join(outputDir, `${baseName}.json`)
+  await writeFile(jsonPath, JSON.stringify(report, null, 2), 'utf-8')
+
+  // Save Markdown report
+  const mdPath = join(outputDir, `${baseName}.md`)
+  await writeFile(mdPath, generateMarkdownReport(report), 'utf-8')
+
+  console.log(`\n📄 Reports saved:`)
+  console.log(`   - JSON: ${jsonPath}`)
+  console.log(`   - Markdown: ${mdPath}`)
+}
+
+/**
+ * Print report summary to console
+ */
+export function printReportSummary(report: MigrationReport): void {
+  console.log(`\n${'='.repeat(60)}`)
+  console.log(`📊 MIGRATION REPORT`)
+  console.log(`${'='.repeat(60)}`)
+  console.log(``)
+  console.log(`Mode: ${report.dryRun ? '🧪 Dry Run' : '✅ Live'}`)
+  console.log(``)
+  console.log(`Summary:`)
+  console.log(`  Total:   ${report.summary.total}`)
+  console.log(`  Created: ${report.summary.created} ✅`)
+  console.log(`  Skipped: ${report.summary.skipped} ⏭️`)
+  console.log(`  Failed:  ${report.summary.failed} ❌`)
+  console.log(``)
+
+  if (report.byCollection) {
+    console.log(`By Collection:`)
+    for (const [collection, stats] of Object.entries(report.byCollection)) {
+      console.log(
+        `  ${collection}: ${stats.created} created, ${stats.skipped} skipped, ${stats.failed} failed`,
+      )
+    }
+  }
+
+  console.log(`${'='.repeat(60)}`)
+}