fix(apiserver): enforce self_ug job scopes and accept project filters (bug-1934, bug-1935)

bug-1934: every job-permission check read a single scope and compared it
only with "self", so a job:view or job:control grant scoped to self_ug acted
like "all" (list, get by ID, control), and self + self_ug collapsed to self.
userJobScope() now collects all of a user's grants of a job permission
before deduplication and adds them up (all; self; self_ug = the user and
everyone sharing a user group). The job list appends a submit_user filter
for narrower scopes, get-by-ID keeps covered rows in a new slice (removing
from the ranged slice skipped rows) and answers 403, both control paths
and job output check the owner against the scope. User groups now reach
the apiserver: the config push converts cluster_config_t.ugroups and
OnUserGroupsUpdated() replaces the new store (nested groups, all,
exclusions). The default basic_user now also sees its user-group mates'
jobs, as its configuration says.

bug-1935: project_name and license_project are accepted job filters, so
xcecli jobs list -P works.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/frontend/apiserver/backend/handler.go

@@ -192,6 +192,11 @@ func (h *DefaultHandler) OnClusterUpdated(incoming *models.ClusterInfo) {
 	SetHeartbeatInterval(incoming.HeartbeatInterval)
 }
 
+// OnUserGroupsUpdated replaces the stored user groups as a whole.
+func (h *DefaultHandler) OnUserGroupsUpdated(groups []models.UserGroupInfo) {
+	store.SetUserGroups(groups)
+}
+
 func (h *DefaultHandler) OnResourceUpdated(res *models.ResourceDefinitionInfo) {
 	store.Resources.Put(res.ResourceName, *res)
 }