refactor: remove OIDC env var config and seeder

OIDC configuration is already fully database-backed (oidc_config table,
admin API, OidcConfigRepository). Remove the redundant env var binding
(SecurityProperties.Oidc), the env-to-DB seeder (oidcConfigSeeder), and
the OIDC section from application.yml.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/main/resources/application.yml

@@ -53,13 +53,7 @@ security:
   ui-password: ${CAMELEER_UI_PASSWORD:admin}
   ui-origin: ${CAMELEER_UI_ORIGIN:http://localhost:5173}
   jwt-secret: ${CAMELEER_JWT_SECRET:}
-  oidc:
-    enabled: ${CAMELEER_OIDC_ENABLED:false}
-    issuer-uri: ${CAMELEER_OIDC_ISSUER:}
-    client-id: ${CAMELEER_OIDC_CLIENT_ID:}
-    client-secret: ${CAMELEER_OIDC_CLIENT_SECRET:}
-    roles-claim: ${CAMELEER_OIDC_ROLES_CLAIM:realm_access.roles}
-    default-roles: ${CAMELEER_OIDC_DEFAULT_ROLES:VIEWER}
+
 
 springdoc:
   api-docs: