fix: add revised migration

src/entities/Link.ts

@@ -4,27 +4,44 @@ import { User } from "./User"
 @Entity("links")
 export class Link {
 
+	// Unique link id.
 	@PrimaryGeneratedColumn()
 	id: number
 
+	// Experimental: subdomain which should be a part of the short url.
+	// For instance in the URL "abc.example.com/def", abc is the subdomain.
+	// "def.example.com/def" won't resolve to the URL that "abc.example.com/def" does.
 	@Column({ nullable: true })
 	subdomain: string | null
 
+	// Shortened Uri.
 	@Column()
 	shortUri: string
 
+	// URL to which the user should be redirected
 	@Column()
 	fullUrl: string
 
-	@Column()
-	role: string
-
+	// Unix timestamp of link creation date.
 	@Column('bigint')
 	createDate: number
 
-	@Column('bigint')
-	expiryDate: number
+	// Unix timestamp of when the link should expire.
+	// If null, the link will never expire unless deleted.
+	@Column('bigint', { nullable: true })
+	expiryDate: number | null
 
+	// Aggregated amount of visits.
+	@Column('bigint')
+	visits: number
+
+	// Link privacy:
+	// - true, if link is private
+	// - false, if link can be shown in a list of recent links publicly.
+	@Column()
+	privacy: boolean
+
+	// User to which the shortened URL belongs.
 	@ManyToOne(() => User, (user) => user.links, { nullable: true })
 	@JoinTable()
 	author: User | null