feat(cms): LegalPages collection + migration (MITHOME-88)

Slug-based collection mirroring LegalPageContent (proto/src/content/
types.ts) for the two legal pages (adatvedelem, hasznalati-feltetelek).

- src/collections/LegalPages.ts: slug (unique), title, lastUpdated,
  sections[] (id/title/content). `content` stays a plain textarea, not
  lexical richText — the current frontend
  (src/app/(frontend)/adatvedelem/page.tsx) renders it through a
  hand-rolled "•"/"**bold**" regex converter, not a real Markdown/
  richText parser, matching the same bootstrap-scope call made for
  Contact.gdpr.label in MITHOME-87.
- Registered in payload.config.ts.
- migrate-content-to-payload.ts: added an idempotent upsertLegalPage
  helper (find-by-slug, then update or create — Collections don't have
  Globals' fixed-slug updateGlobal) and seeded both legal pages from
  their existing JSON.

Verified: migration run twice against the real dev MongoDB produced
exactly 2 documents (no duplicates) — confirmed via mongosh. Real
browser: logged into /admin, Legal Pages list shows both entries with
correct titles/slugs, opened the adatvedelem document and the slug/
title/body fields all show the migrated content correctly. build/lint/
tsc/test (58 passed) all clean.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

proto/scripts/migrate-content-to-payload.ts

@@ -1,16 +1,18 @@
 /**
- * MITHOME-87: egyszeri migrációs script — a proto/src/content/pages/*.json
+ * MITHOME-87/88: egyszeri migrációs script — a proto/src/content/pages/*.json
  * + common.json tartalmát átemeli a Payload Globals-ekbe (Home, About,
- * Services, Contact, Common) a Local API-n keresztül.
+ * Services, Contact, Common) és a LegalPages collection-be a Local API-n
+ * keresztül.
  *
  * Futtatás (proto/ mappából, futó MongoDB-vel és beállított env-ekkel):
  *   node --env-file=.env.local --import tsx scripts/migrate-content-to-payload.ts
  *
- * Idempotens: updateGlobal-t hív, tetszőlegesen többször futtatható —
- * mindig a JSON az aktuális "forrás igazság", felülírja a Payload-ban
- * lévő korábbi állapotot. NEM törli/nem érinti a JSON fájlokat.
+ * Idempotens: updateGlobal-t / slug-alapú upsert-et hív, tetszőlegesen
+ * többször futtatható — mindig a JSON az aktuális "forrás igazság", felül-
+ * írja a Payload-ban lévő korábbi állapotot. NEM törli/nem érinti a JSON
+ * fájlokat.
  */
-import { getPayload } from 'payload'
+import { getPayload, type Payload } from 'payload'
 import config from '../src/payload.config'
 
 import homeJson from '../src/content/pages/home.json'
@@ -18,6 +20,8 @@ import aboutJson from '../src/content/pages/about.json'
 import servicesJson from '../src/content/pages/services.json'
 import contactJson from '../src/content/pages/contact.json'
 import commonJson from '../src/content/common.json'
+import adatvedelemJson from '../src/content/pages/adatvedelem.json'
+import hasznalatiFeltetelekJson from '../src/content/pages/hasznalati-feltetelek.json'
 
 /** string[] -> [{ value: string }] — lásd src/globals/fields/stringArray.ts */
 function toStringArray(items: readonly string[]): { value: string }[] {
@@ -76,6 +80,35 @@ function buildServicesData(json: typeof servicesJson) {
   }
 }
 
+type LegalPageJson = {
+  title: string
+  lastUpdated: string
+  sections: { id: string; title: string; content: string }[]
+}
+
+/** Collections have no per-document "known slug" API like Globals do —
+ * find-by-slug, then update or create. Idempotent across re-runs. */
+async function upsertLegalPage(payload: Payload, slug: string, json: LegalPageJson) {
+  const existing = await payload.find({
+    collection: 'legal-pages',
+    where: { slug: { equals: slug } },
+    limit: 1,
+  })
+
+  if (existing.docs.length > 0) {
+    await payload.update({
+      collection: 'legal-pages',
+      id: existing.docs[0].id,
+      data: { slug, ...json },
+    })
+  } else {
+    await payload.create({
+      collection: 'legal-pages',
+      data: { slug, ...json },
+    })
+  }
+}
+
 async function run() {
   const payload = await getPayload({ config })
 
@@ -94,7 +127,13 @@ async function run() {
   await payload.updateGlobal({ slug: 'common', data: commonJson })
   payload.logger.info('Common global migrálva')
 
-  payload.logger.info('MITHOME-87 migráció kész.')
+  await upsertLegalPage(payload, 'adatvedelem', adatvedelemJson)
+  payload.logger.info('LegalPages/adatvedelem migrálva')
+
+  await upsertLegalPage(payload, 'hasznalati-feltetelek', hasznalatiFeltetelekJson)
+  payload.logger.info('LegalPages/hasznalati-feltetelek migrálva')
+
+  payload.logger.info('MITHOME-87/88 migráció kész.')
   process.exit(0)
 }