feat(pagination): add generic typed pagination with ordering to all list endpoints

- add PaginationQueryDto<TOrderBy> generic with orderBy and orderDir fields
- add SessionOrderBy, EnvironmentOrderBy, ScenarioOrderBy type aliases
- update session, environment, scenario services and controllers to use typed pagination
- update MCP list_sessions, list_environments, list_scenarios tools to expose orderBy/orderDir
- update tests for all list endpoints to cover page, limit, ordering, and invalid param rejection

test/scenario.controller.spec.ts

@@ -68,16 +68,44 @@ describe('ScenarioController', () => {
     });
 
     it('respects page and limit params', async () => {
+      await createScenario('paged-sc-a');
+      await createScenario('paged-sc-b');
+
       const res = await request(app.getHttpServer())
-        .get('/scenarios?page=1&limit=2')
+        .get('/scenarios?page=1&limit=1')
         .expect(200);
-      expect(res.body.limit).toBe(2);
+      expect(res.body.data).toHaveLength(1);
+      expect(res.body.limit).toBe(1);
       expect(res.body.page).toBe(1);
     });
 
+    it('returns empty data for out-of-range page', async () => {
+      const res = await request(app.getHttpServer()).get('/scenarios?page=9999&limit=20').expect(200);
+      expect(res.body.data).toHaveLength(0);
+    });
+
     it('returns 400 for invalid pagination params', async () => {
       await request(app.getHttpServer()).get('/scenarios?page=0').expect(400);
     });
+
+    it('orders by name ASC', async () => {
+      await createScenario('zzz-order-sc');
+      await createScenario('aaa-order-sc');
+
+      const res = await request(app.getHttpServer()).get('/scenarios?orderBy=name&orderDir=ASC').expect(200);
+      const names: string[] = res.body.data.map((s: any) => s.name);
+      expect(names).toEqual([...names].sort());
+    });
+
+    it('orders by name DESC', async () => {
+      const res = await request(app.getHttpServer()).get('/scenarios?orderBy=name&orderDir=DESC').expect(200);
+      const names: string[] = res.body.data.map((s: any) => s.name);
+      expect(names).toEqual([...names].sort().reverse());
+    });
+
+    it('returns 400 for invalid orderDir', async () => {
+      await request(app.getHttpServer()).get('/scenarios?orderDir=SIDEWAYS').expect(400);
+    });
   });
 
   // ── GET /scenarios/:id ─────────────────────────────────────────────────────