changesets: updated and added changesets for app auth

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/nine-rabbits-exist.md

@@ -1,5 +1,6 @@
 ---
 '@backstage/core-app-api': patch
+'@backstage/frontend-app-api': patch
 ---
 
-Clear the app auth cookie after a sign out.
+The app is now aware of if it is being served from the `app-backend` with a separate public and protected bundles. When in protected mode the app will now continuously refresh the session cookie, as well as clear the cookie if the user signs out.

.changeset/tall-rats-pull.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+When building the frontend app public assets are now also copied to the public dist directory when in use.

.changeset/weak-planets-move.md

@@ -0,0 +1,5 @@
+---
+'@backstage/backend-plugin-api': patch
+---
+
+The credentials passed to the `issueUserCookie` method of the `HttpAuthService` are no longer required to represent a user principal.