feat: Authors feature backend (and upgraded deprecated mods)

api/pkg/apperr/messages.go

@@ -67,3 +67,17 @@ const InvalidLocaleErrorMessage = "invalid_locale"
 const SiteImageNotFoundErrorMessage = "image_not_found"
 const UseSetDefaultErrorMessage = "use_set_default"
 const InvalidReassignErrorMessage = "invalid_reassign"
+const InvalidSocialTypeErrorMessage = "invalid_social_type"
+
+const AuthorNotFoundErrorMessage = "author_not_found"
+const AuthorSlugTakenErrorMessage = "author_slug_taken"
+const AuthorHasArticlesErrorMessage = "author_has_articles"
+const UserAlreadyLinkedErrorMessage = "user_already_linked"
+const AuthorAlreadyLinkedErrorMessage = "author_already_linked"
+const UserNotFoundErrorMessage = "user_not_found"
+const AuthorRightsErrorMessage = "author_rights"
+const BioTooLongErrorMessage = "bio_too_long"
+const InvalidURLErrorMessage = "invalid_url"
+const TooManyLinksErrorMessage = "too_many_links"
+const InvalidSlugErrorMessage = "invalid_slug"
+const AuthorImageNotFoundErrorMessage = "image_not_found"