fix(jenkins): render exactly one trailing slash on the root url

url.base already ends in a slash, so appending one produced
https://host// and Jenkins rejected it as invalid, leaving the root url
null. Every API then answered 500: /api/json, /whoAmI/api/json and
/me/api/json alike, while the MCP plugin itself had started fine.

Drop the two comment blocks the comment lint flagged once this file was
touched. Their content: since oic-auth 4.x the flat tokenServerUrl /
authorizationServerUrl / scopes keys fail boot with "Invalid
configuration elements" and only the nested serverConfiguration.wellKnown
form loads; role-strategy renamed assignments to entries with typed
user/group objects and rejects the old bare-string list with
"'assignments' is deprecated".

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

roles/web-app-jenkins/templates/casc.yaml.j2

@@ -11,13 +11,6 @@ jenkins:
 
 {% if JENKINS_OIDC_ENABLED | bool %}
   securityRealm:
-    # The `oic-auth` plugin (>= 4.x) restructured its JCasC schema:
-    # endpoint URLs and the well-known discovery URL now live inside a
-    # nested `serverConfiguration.wellKnown` block; flat keys like
-    # `tokenServerUrl`/`authorizationServerUrl`/`scopes` fail boot
-    # with `Invalid configuration elements`. Driving via the
-    # well-known discovery URL only — Keycloak's discovery doc carries
-    # all endpoints, scopes overrides not needed.
     oic:
       clientId: "{{ OIDC.CLIENT.ID }}"
       clientSecret: "{{ OIDC.CLIENT.SECRET }}"
@@ -48,11 +41,6 @@ jenkins:
 {% endif %}
 
   authorizationStrategy:
-    # The role-strategy plugin renamed `assignments` to `entries` and
-    # made each entry an explicit `{user|group}` typed object — the old
-    # bare-string list fails JCasC validation with
-    # `'assignments' is deprecated`. See
-    # https://plugins.jenkins.io/role-strategy/#configuration-as-code-support
     roleBased:
       roles:
         global:
@@ -65,4 +53,4 @@ jenkins:
               - group: "authenticated"
 unclassified:
   location:
-    url: "{{ lookup('tls', application_id, 'url.base') }}/"
+    url: "{{ lookup('tls', application_id, 'url.base') | regex_replace('/+$', '') }}/"