fix: address code review findings for analytics and security

shared/modules/dashboard/dashboard.service.test.ts

@@ -227,5 +227,66 @@ describe("dashboardService", () => {
             expect(otherHour?.transactions).toBe(0);
             expect(otherHour?.commands).toBe(0);
         });
+
+        test("should return 24 hours of zeros if database is empty", async () => {
+            mockSelect.mockImplementationOnce(() => ({
+                // @ts-ignore
+                from: mock(() => ({
+                    where: mock(() => ({
+                        groupBy: mock(() => ({
+                            orderBy: mock(() => Promise.resolve([]))
+                        }))
+                    }))
+                }))
+            }));
+
+            const activity = await dashboardService.getActivityAggregation();
+            expect(activity).toHaveLength(24);
+            expect(activity.every(a => a.transactions === 0 && a.commands === 0)).toBe(true);
+        });
+
+        test("should return 24 hours of zeros if database returns rows with null hours", async () => {
+            mockSelect.mockImplementationOnce(() => ({
+                // @ts-ignore
+                from: mock(() => ({
+                    where: mock(() => ({
+                        groupBy: mock(() => ({
+                            orderBy: mock(() => Promise.resolve([{ hour: null, transactions: "10", commands: "5" }]))
+                        }))
+                    }))
+                }))
+            }));
+
+            const activity = await dashboardService.getActivityAggregation();
+            expect(activity).toHaveLength(24);
+            expect(activity.every(a => a.transactions === 0 && a.commands === 0)).toBe(true);
+        });
+
+        test("should correctly map hours regardless of input sort order", async () => {
+            const now = new Date();
+            now.setHours(now.getHours(), 0, 0, 0);
+            const hourAgo = new Date(now.getTime() - 60 * 60 * 1000);
+
+            mockSelect.mockImplementationOnce(() => ({
+                // @ts-ignore
+                from: mock(() => ({
+                    where: mock(() => ({
+                        groupBy: mock(() => ({
+                            orderBy: mock(() => Promise.resolve([
+                                { hour: now.toISOString(), transactions: "10", commands: "5" },
+                                { hour: hourAgo.toISOString(), transactions: "20", commands: "10" }
+                            ]))
+                        }))
+                    }))
+                }))
+            }));
+
+            const activity = await dashboardService.getActivityAggregation();
+            const current = activity.find(a => a.hour === now.toISOString());
+            const past = activity.find(a => a.hour === hourAgo.toISOString());
+
+            expect(current?.transactions).toBe(10);
+            expect(past?.transactions).toBe(20);
+        });
     });
 });