移除示例项目初始化并修复前后端稳定性问题

frontend/src/views/admin/Projects.vue

@@ -58,7 +58,7 @@
         </el-table>
       </div>
     </div>
-    <ProjectForm v-model:visible="formVisible" :project="editingProject" @saved="loadProjects" />
+    <ProjectForm v-if="formVisible" v-model:visible="formVisible" :project="editingProject" @saved="loadProjects" />
   </div>
 </template>
 
@@ -139,7 +139,11 @@ const handleDelete = async (study: Study) => {
       return;
     }
     
+    const isDeletingCurrentStudy = studyStore.currentStudy?.id === study.id;
     await deleteStudy(study.id);
+    if (isDeletingCurrentStudy) {
+      await studyStore.rehydrateStudyForLastUser({ preferActive: true });
+    }
     ElMessage.success("项目已删除");
     await loadProjects();
   } catch (err: any) {