feat: add job_count and project_count to environment list API

BE: Query UserTaskDetails and ProjectDetails counts per environment
FE: Wire "Used by" column to show "X jobs · Y projects" from API data

Author: wicky-zipstack

backend/backend/application/session/env_session.py

@@ -6,6 +6,7 @@
 from backend.application.utils import get_filter
 from backend.core.models.environment_models import EnvironmentModels
 from backend.core.models.project_details import ProjectDetails
+from backend.core.scheduler.models import UserTaskDetails
 from backend.errors.exceptions import EnvironmentAlreadyExist, EnvironmentNotExists
 from backend.utils.pagination import CustomPaginator
 
@@ -89,6 +90,12 @@ def get_all_environments(self, page: int, limit: int, filter_condition: dict[str
 
         env_data = []
         for env_model in env_models.get("page_items"):
+            job_count = UserTaskDetails.objects.filter(
+                environment=env_model
+            ).count()
+            project_count = ProjectDetails.objects.filter(
+                environment_model=env_model
+            ).count()
             env_data.append(
                 {
                     "id": env_model.environment_id,
@@ -104,6 +111,8 @@ def get_all_environments(self, page: int, limit: int, filter_condition: dict[str
                         "connection_flag": env_model.connection_model.connection_flag,
                     },
                     "is_tested": env_model.is_tested,
+                    "job_count": job_count,
+                    "project_count": project_count,
                 }
             )
         env_models["page_items"] = env_data

frontend/src/base/components/environment/EnvList.jsx

@@ -304,11 +304,28 @@ const EnvList = () => {
         title: "Used by",
         key: "usedBy",
         width: 140,
-        render: () => (
-          <Text type="secondary" style={{ fontSize: 12 }}>
-            —
-          </Text>
-        ),
+        render: (_, record) => {
+          const jobs = record.job_count || 0;
+          const projects = record.project_count || 0;
+          if (jobs === 0 && projects === 0) {
+            return (
+              <Text
+                type="secondary"
+                style={{ fontSize: 12, fontStyle: "italic" }}
+              >
+                Not used
+              </Text>
+            );
+          }
+          return (
+            <Text type="secondary" style={{ fontSize: 12 }}>
+              {jobs > 0 && `${jobs} job${jobs !== 1 ? "s" : ""}`}
+              {jobs > 0 && projects > 0 && " · "}
+              {projects > 0 &&
+                `${projects} project${projects !== 1 ? "s" : ""}`}
+            </Text>
+          );
+        },
       },
       {
         title: "Actions",