feat(analytics): add custom metadata support for shared links

- Add custom title field for user-defined link names
- Implement custom OG image URL input for social media previews
- Enable Open Graph metadata customization (description, type, etc.)
- Add link slug/path customization for personalized URLs
- Update link creation form with new metadata fields
- Extend database schema to store custom link properties
- Add validation for OG image URLs and metadata inputs

This allows users to fully customize their shared analytics links with
custom titles, Open Graph images, and other metadata for better social
media presentation and link management.

prisma/schema.prisma

@@ -281,6 +281,9 @@ model Link {
   name      String    @db.VarChar(100)
   url       String    @db.VarChar(500)
   slug      String    @unique() @db.VarChar(100)
+  title     String?   @db.VarChar(500)
+  description String? @db.VarChar(500)
+  image     String?   @db.VarChar(500)
   userId    String?   @map("user_id") @db.Uuid
   teamId    String?   @map("team_id") @db.Uuid
   createdAt DateTime? @default(now()) @map("created_at") @db.Timestamptz(6)