feat(task): auto-inject scheduling params into script template via scheduling_map

Add scheduling_map field to ParameterSchema so Application creators can
declare that a parameter (e.g. NP) maps to a scheduling field (e.g. cpus).
The backend auto-injects the scheduling value into script template variables
before rendering, eliminating duplicate user input. The frontend hides
mapped parameters from the form and injects their values on submit.

internal/service/cluster_service.go

@@ -42,6 +42,13 @@ func derefInt32ToStr(i *int32) string {
 	return strconv.FormatInt(int64(*i), 10)
 }
 
+func derefInt64ToStr(i *int64) string {
+	if i == nil {
+		return ""
+	}
+	return strconv.FormatInt(*i, 10)
+}
+
 func uint32NoValString(v *slurm.Uint32NoVal) string {
 	if v == nil {
 		return ""