web-app-minio: enable OIDC integration and policy handling

- Added OIDC and LDAP feature flags in config
- Introduced API/Console URL vars for proxy alignment
- Implemented automatic MinIO policy creation for OIDC admin group
- Replaced static env.J2 with dynamic env.j2 (OIDC-aware)
- Added policy.json.j2 template with full admin rights
- Cleaned up tasks to use stdin instead of file for mc policy apply

Ref: https://chatgpt.com/share/68d1d3ef-ca84-800f-abe2-11ab70e20c4e

roles/web-app-minio/config/main.yml

@@ -6,6 +6,8 @@ features:
   logout:           true
   javascript:       false
   local_ai:         true
+  oidc:             true
+  ldap:             false # OIDC is already activated so LDAP isn't necessary
 server:
   domains:
     canonical:
@@ -22,7 +24,7 @@ server:
       #style-src:
       #  unsafe-inline:  true
     whitelist:
-      font-src: [] 
+      font-src: []
       connect-src: [] 
 docker:
   services: