feat(service): add GetJob fallback to SlurmDBD history and expand query params

GetJob now falls back to SlurmDBD history when active queue returns 404 or empty jobs. Expand JobHistoryQuery from 7 to 16 filter params (add SubmitTime, Cluster, Qos, Constraints, ExitCode, Node, Reservation, Groups, Wckey).

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/service/job_service_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 
 	"gcy_hpc_server/internal/model"
@@ -701,3 +702,157 @@ func TestJobService_GetJobHistory_ErrorLog(t *testing.T) {
 		t.Error("expected error field in log entry")
 	}
 }
+
+// ---------------------------------------------------------------------------
+// Fallback to SlurmDBD history tests
+// ---------------------------------------------------------------------------
+
+func TestGetJob_FallbackToHistory_Found(t *testing.T) {
+	jobID := int32(198)
+	name := "hist-job"
+	ts := int64(1700000000)
+
+	client, cleanup := mockJobServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+
+		switch r.URL.Path {
+		case "/slurm/v0.0.40/job/198":
+			w.WriteHeader(http.StatusNotFound)
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"errors": []map[string]interface{}{
+					{
+						"description":  "Unable to query JobId=198",
+						"error_number": float64(2017),
+						"error":        "Invalid job id specified",
+						"source":       "_handle_job_get",
+					},
+				},
+				"jobs": []interface{}{},
+			})
+		case "/slurmdb/v0.0.40/job/198":
+			resp := slurm.OpenapiSlurmdbdJobsResp{
+				Jobs: slurm.JobList{
+					{
+						JobID: &jobID,
+						Name:  &name,
+						State: &slurm.JobState{Current: []string{"COMPLETED"}},
+						Time:  &slurm.JobTime{Submission: &ts, Start: &ts, End: &ts},
+					},
+				},
+			}
+			json.NewEncoder(w).Encode(resp)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer cleanup()
+
+	svc := NewJobService(client, zap.NewNop())
+	job, err := svc.GetJob(context.Background(), "198")
+	if err != nil {
+		t.Fatalf("GetJob: %v", err)
+	}
+	if job == nil {
+		t.Fatal("expected job, got nil")
+	}
+	if job.JobID != 198 {
+		t.Errorf("expected JobID 198, got %d", job.JobID)
+	}
+	if job.Name != "hist-job" {
+		t.Errorf("expected Name hist-job, got %s", job.Name)
+	}
+}
+
+func TestGetJob_FallbackToHistory_NotFound(t *testing.T) {
+	client, cleanup := mockJobServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	defer cleanup()
+
+	svc := NewJobService(client, zap.NewNop())
+	job, err := svc.GetJob(context.Background(), "999")
+	if err != nil {
+		t.Fatalf("GetJob: %v", err)
+	}
+	if job != nil {
+		t.Errorf("expected nil, got %+v", job)
+	}
+}
+
+func TestGetJob_FallbackToHistory_HistoryError(t *testing.T) {
+	client, cleanup := mockJobServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+
+		switch r.URL.Path {
+		case "/slurm/v0.0.40/job/500":
+			w.WriteHeader(http.StatusNotFound)
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"errors": []map[string]interface{}{
+					{
+						"description":  "Unable to query JobId=500",
+						"error_number": float64(2017),
+						"error":        "Invalid job id specified",
+						"source":       "_handle_job_get",
+					},
+				},
+				"jobs": []interface{}{},
+			})
+		case "/slurmdb/v0.0.40/job/500":
+			w.WriteHeader(http.StatusInternalServerError)
+			w.Write([]byte(`{"errors":[{"error":"db error"}]}`))
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer cleanup()
+
+	svc := NewJobService(client, zap.NewNop())
+	job, err := svc.GetJob(context.Background(), "500")
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+	if job != nil {
+		t.Errorf("expected nil job, got %+v", job)
+	}
+	if !strings.Contains(err.Error(), "get job history") {
+		t.Errorf("expected error to contain 'get job history', got %s", err.Error())
+	}
+}
+
+func TestGetJob_FallbackToHistory_EmptyHistory(t *testing.T) {
+	client, cleanup := mockJobServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+
+		switch r.URL.Path {
+		case "/slurm/v0.0.40/job/777":
+			w.WriteHeader(http.StatusNotFound)
+			json.NewEncoder(w).Encode(map[string]interface{}{
+				"errors": []map[string]interface{}{
+					{
+						"description":  "Unable to query JobId=777",
+						"error_number": float64(2017),
+						"error":        "Invalid job id specified",
+						"source":       "_handle_job_get",
+					},
+				},
+				"jobs": []interface{}{},
+			})
+		case "/slurmdb/v0.0.40/job/777":
+			resp := slurm.OpenapiSlurmdbdJobsResp{Jobs: slurm.JobList{}}
+			json.NewEncoder(w).Encode(resp)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	}))
+	defer cleanup()
+
+	svc := NewJobService(client, zap.NewNop())
+	job, err := svc.GetJob(context.Background(), "777")
+	if err != nil {
+		t.Fatalf("GetJob: %v", err)
+	}
+	if job != nil {
+		t.Errorf("expected nil, got %+v", job)
+	}
+}