Remove plaintext htpasswd Secret from git (filebrowser)

Phase 3c of migration #2: drop the Secret stanza from auth.yaml; the Middleware
stays and references filebrowser-auth-infisical (synced from homelab/prod
/filebrowser). ArgoCD prunes the old plaintext filebrowser-auth secret — the
bcrypt htpasswd leaves git. Completes migration #2.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

filebrowser/auth.yaml

@@ -1,17 +1,8 @@
 ---
-# Basic-auth credentials in htpasswd format (bcrypt-hashed).
-# Generated with: htpasswd -nbB chemavx <password>
-apiVersion: v1
-kind: Secret
-metadata:
-  name: filebrowser-auth
-  namespace: filebrowser
-type: Opaque
-stringData:
-  users: |
-    chemavx:$2b$12$a1vb6zKuvbpvw8XWJk2ZYeAZtLGkJ.VsdOuMQhC5HmdC0cdnLzNhC
-
----
+# Basic-auth for files.chemavx.xyz. The htpasswd credentials are no longer in
+# git — they live in Infisical (homelab/prod /filebrowser FILEBROWSER_USERS) and
+# are synced into the Secret `filebrowser-auth-infisical` by the InfisicalStaticSecret
+# in infisical-auth.yaml. This Middleware references that synced Secret.
 apiVersion: traefik.io/v1alpha1
 kind: Middleware
 metadata: