Fix proxy/projects pages: error handling when API unavailable

- proxy: .catch() shows 'service not ready' instead of stuck loading
- projects: shows 'engine not ready' on API error
- Both: show 'no items' placeholder instead of blank

static/web_panel/pages/projects.html

@@ -38,7 +38,7 @@
 var projects=[];
 function showTab(e,t){document.querySelectorAll("#tab-running,#tab-add,#tab-git").forEach(el=>el.style.display="none");document.getElementById("tab-"+t).style.display="block";document.querySelectorAll(".tab").forEach(el=>el.classList.remove("active"));e.target.classList.add("active")}
 async function refresh(){
-  try{var r=await fetch("/SenSu/api/projects");var d=await r.json();projects=d.projects;var h="";for(var p of projects){var cls=p.status==="running"?"status-running":p.status==="error"?"status-error":"status-stopped";h+='<div class="mgmt-card"><div class="status-dot '+cls+'"></div><div class="info"><b>'+p.name+'</b><br><small>'+p.status+" PID:"+(p.pid||"-")+" :"+(p.port||"-")+" "+(p.uptime?p.uptime+"s":"")+(p.proxy?" → "+p.proxy:"")+'</small></div><div class="actions"><button class="btn btn-sm btn-danger" onclick="stopP(this,'+JSON.stringify(p.name)+')">停止</button><button class="btn btn-sm btn-outlined" onclick="logsP(this,'+JSON.stringify(p.name)+')">日志</button><button class="btn btn-sm btn-text" onclick="cmdP(this,'+JSON.stringify(p.name)+')">命令</button></div></div><div class="log-box" id="logs-'+p.name+'"></div>'}document.getElementById("project-list").innerHTML=h||"暂无项目"}catch(e){console.error(e)}
+  try{var r=await fetch("/SenSu/api/projects");var d=await r.json();projects=d.projects;var h="";for(var p of projects){var cls=p.status==="running"?"status-running":p.status==="error"?"status-error":"status-stopped";h+='<div class="mgmt-card"><div class="status-dot '+cls+'"></div><div class="info"><b>'+p.name+'</b><br><small>'+p.status+" PID:"+(p.pid||"-")+" :"+(p.port||"-")+" "+(p.uptime?p.uptime+"s":"")+(p.proxy?" → "+p.proxy:"")+'</small></div><div class="actions"><button class="btn btn-sm btn-danger" onclick="stopP(this,'+JSON.stringify(p.name)+')">停止</button><button class="btn btn-sm btn-outlined" onclick="logsP(this,'+JSON.stringify(p.name)+')">日志</button><button class="btn btn-sm btn-text" onclick="cmdP(this,'+JSON.stringify(p.name)+')">命令</button></div></div><div class="log-box" id="logs-'+p.name+'"></div>'}document.getElementById("project-list").innerHTML=h||"<div style=\"color:var(--text-dim);text-align:center;padding:40px\">暂无项目</div>"}catch(e){document.getElementById("project-list").innerHTML="<div style=\"color:var(--error);text-align:center;padding:40px\">引擎未就绪 (API 错误)</div>"}
 }
 async function addProject(){
   var n=document.getElementById("proj-name").value,cmd=document.getElementById("proj-cmd").value;

static/web_panel/pages/proxy.html

@@ -14,12 +14,14 @@
 
 <script>
 function refresh(){
-  fetch("/SenSu/api/proxy").then(r=>r.json()).then(d=>{
+  fetch("/SenSu/api/proxy").then(r=>{if(!r.ok)throw new Error(r.status);return r.json()}).then(d=>{
     var h="";
     for(var p of d.proxies||[]){
       h+='<div class="mgmt-card"><div class="status-dot status-running"></div><div class="info"><b>'+p.path+'</b><br><small>→ '+p.target+(p.description?" ("+p.description+")":"")+(p.external?" 🌐":"")+'</small></div><div class="actions"><button class="btn btn-sm btn-danger" onclick="delP(\"'+p.path+'\")">删除</button></div></div>';
     }
-    document.getElementById("proxy-list").innerHTML=h||"暂无代理"
+    document.getElementById("proxy-list").innerHTML=h||"<div style=\"color:var(--text-dim);text-align:center;padding:40px\">暂无代理配置</div>"
+  }).catch(function(e){
+    document.getElementById("proxy-list").innerHTML="<div style=\"color:var(--error);text-align:center;padding:40px\">代理服务未就绪 (API 返回 "+e.message+")</div>"
   })
 }
 function addP(){