feat(birthday): upload fields for why-section videos

Replace text src/poster in whyVideos with media upload pickers so
admins can upload video files directly from the CMS instead of
entering raw URLs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

migrations/0015_birthday_why_videos_upload.sql

@@ -0,0 +1,14 @@
+-- 0015: replace text src/poster in birthday_page_why_videos with media FK uploads
+
+ALTER TABLE "birthday_page_why_videos"
+  ADD COLUMN IF NOT EXISTS "video_id" integer
+    REFERENCES "media"("id") ON DELETE SET NULL ON UPDATE NO ACTION,
+  ADD COLUMN IF NOT EXISTS "poster_id" integer
+    REFERENCES "media"("id") ON DELETE SET NULL ON UPDATE NO ACTION;
+
+-- versions mirror
+ALTER TABLE "_birthday_page_v_version_why_videos"
+  ADD COLUMN IF NOT EXISTS "video_id" integer
+    REFERENCES "media"("id") ON DELETE SET NULL ON UPDATE NO ACTION,
+  ADD COLUMN IF NOT EXISTS "poster_id" integer
+    REFERENCES "media"("id") ON DELETE SET NULL ON UPDATE NO ACTION;

src/app/(frontend)/dni-narodzhennia/page.tsx

@@ -423,11 +423,13 @@ export default async function BirthdayPage() {
         items={whyItems.map((i) => ({ title: i.title, description: i.description }))}
         reviewVideos={
           whyVideos.length > 0
-            ? whyVideos.map((v) => ({
-                src: v.src as string,
-                poster: (v.poster as string) ?? null,
-                label: (v.label as string) ?? null,
-              }))
+            ? whyVideos
+                .map((v) => ({
+                  src: mediaUrl(v.video as Media | undefined) ?? (v.src as string) ?? '',
+                  poster: mediaUrl(v.poster as Media | undefined) ?? null,
+                  label: (v.label as string) ?? null,
+                }))
+                .filter((v) => v.src)
             : undefined
         }
       />

src/globals/BirthdayPage.ts

@@ -130,9 +130,21 @@ export const BirthdayPage: GlobalConfig = {
       type: 'array',
       label: 'Відео-відгуки у секції "Чому"',
       fields: [
-        { name: 'src', type: 'text', required: true },
-        { name: 'poster', type: 'text' },
-        { name: 'label', type: 'text' },
+        {
+          name: 'video',
+          type: 'upload',
+          relationTo: 'media',
+          required: true,
+          label: 'Відео файл',
+        },
+        {
+          name: 'poster',
+          type: 'upload',
+          relationTo: 'media',
+          required: false,
+          label: 'Постер (обкладинка, опційно)',
+        },
+        { name: 'label', type: 'text', label: 'Підпис (опційно)' },
       ],
     },
     // Working hours