feat: support HTTP redirect for forward authentication middleware in Traefik (#368)

* feat: support HTTP redirect for forward authentication middleware in Traefik

* fix(docs): fix my terrible merge 

Signed-off-by: Jason Cameron <jasoncameron.all@gmail.com>

* chore: fix typo in docs

Signed-off-by: Jason Cameron <jasoncameron.all@gmail.com>

* fix(ci): add forwardauth

Signed-off-by: Jason Cameron <jasoncameron.all@gmail.com>

* chore: improve doc, target must be a space

* chore: changelog

* fix: validate X-Forwarded headers and check redirect domain

* chore: refactor error handling

* fix(doc): cookie traefik

* fix: tests merge

* Update docs/docs/admin/environments/traefik.mdx

Co-authored-by: Henri Vasserman <henv@hot.ee>
Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Jason Cameron <git@jasoncameron.dev>
Signed-off-by: Jason Cameron <jasoncameron.all@gmail.com>
Signed-off-by: Xe Iaso <me@xeiaso.net>
Co-authored-by: Jason Cameron <git@jasoncameron.dev>
Co-authored-by: Jason Cameron <jasoncameron.all@gmail.com>
Co-authored-by: Xe Iaso <me@xeiaso.net>
Co-authored-by: Henri Vasserman <henv@hot.ee>

.github/actions/spelling/expect.txt

@@ -103,6 +103,7 @@ Firecrawl
 flagenv
 Fordola
 forgejo
+forwardauth
 fsys
 fullchain
 gaissmai