backend-common: add api doc comments

Signed-off-by: Mike Lewis <mtlewis@users.noreply.github.com>

packages/backend-common/api-report.md

@@ -526,9 +526,7 @@ export type SearchResponseFile = {
   content(): Promise<Buffer>;
 };
 
-// Warning: (ae-missing-release-tag) "ServerTokenManager" is exported by the package, but it is missing a release tag (@alpha, @beta, @public, or @internal)
-//
-// @public (undocumented)
+// @public
 export class ServerTokenManager implements TokenManager {
   // (undocumented)
   static fromConfig(config: Config): ServerTokenManager;
@@ -599,9 +597,7 @@ export interface StatusCheckHandlerOptions {
   statusCheck?: StatusCheck;
 }
 
-// Warning: (ae-missing-release-tag) "TokenManager" is exported by the package, but it is missing a release tag (@alpha, @beta, @public, or @internal)
-//
-// @public (undocumented)
+// @public
 export interface TokenManager {
   // (undocumented)
   getToken: () => Promise<{

packages/backend-common/src/tokens/ServerTokenManager.ts

@@ -19,6 +19,12 @@ import { Config } from '@backstage/config';
 import { AuthenticationError } from '@backstage/errors';
 import { TokenManager } from './types';
 
+/**
+ * Creates and validates tokens for use during backend-to-backend
+ * authentication.
+ *
+ * @public
+ */
 export class ServerTokenManager implements TokenManager {
   private key: JWK.OctKey | JWK.NoneKey;
 

packages/backend-common/src/tokens/types.ts

@@ -14,6 +14,11 @@
  * limitations under the License.
  */
 
+/**
+ * Interface for creating and validating tokens.
+ *
+ * @public
+ */
 export interface TokenManager {
   getToken: () => Promise<{ token: string }>;
   validateToken: (token: string) => void;