feat(server): added backchannel logout api endpoint (#26235)

* feat(server): added backchannel logout api endpoint

* test(server): fixed e2e tests

* fix(server): fixed suggested changes by reviewer

* feat(server): created function invalidateOAuth

* fix(server): fixed session.repository.sql

* test(server): added unit tests for backchannelLogout function

* test(server): added e2e tests for oidc backchnnel logout

* docs(server): added documentation on backchannel logout url

* docs(server): fixed typo

* feat(server): minor improvements of the oidc backchannel logout

* test(server): fixed tests after merge with main

* fix(server): fixed e2e test file

* refactor(server): tiny refactor of validateLogoutToken

* chore: cleanup

* fix: tests

* fix: make jwks extractable

---------

Co-authored-by: Daniel Dietzler <mail@ddietzler.dev>

server/src/dtos/auth.dto.ts

@@ -124,6 +124,10 @@ const OAuthAuthorizeResponseSchema = z
   })
   .meta({ id: 'OAuthAuthorizeResponseDto' });
 
+const OAuthBackchannelLogoutSchema = z
+  .object({ logout_token: z.string().describe('OAuth logout token') })
+  .meta({ id: 'OAuthBackchannelLogoutDto' });
+
 const AuthStatusResponseSchema = z
   .object({
     pinCode: z.boolean().describe('Has PIN code set'),
@@ -147,4 +151,5 @@ export class ValidateAccessTokenResponseDto extends createZodDto(ValidateAccessT
 export class OAuthCallbackDto extends createZodDto(OAuthCallbackSchema) {}
 export class OAuthConfigDto extends createZodDto(OAuthConfigSchema) {}
 export class OAuthAuthorizeResponseDto extends createZodDto(OAuthAuthorizeResponseSchema) {}
+export class OAuthBackchannelLogoutDto extends createZodDto(OAuthBackchannelLogoutSchema) {}
 export class AuthStatusResponseDto extends createZodDto(AuthStatusResponseSchema) {}