feat(host): 浮窗聊天框打通（apiProxy.sessions.prompt）+ 会话控制路由 + 事件直方图自检

shell/ui.html

@@ -610,8 +610,10 @@
         }
 
         let es = null
+        let ENDPOINT = null
         function setEndpoint(ep) {
             const live = !!(ep && ep.baseUrl)
+            ENDPOINT = live ? ep.baseUrl : null
             $('dot').className = 'dot ' + (live ? 'live' : 'wait')
             $('sub').textContent = live ? ep.baseUrl.replace(/^https?:\/\//, '') : '未连接'
             $('input').disabled = !live
@@ -702,8 +704,26 @@
         const submit = () => {
             const v = $('input').value.trim()
             if (!v) return
-            send({ cmd: 'chat', text: v })
             $('input').value = ''; $('input').style.height = 'auto'
+            if (ENDPOINT) {
+                // 真实发送：POST 给插件，由它走宿主网关送进会话
+                fetch(ENDPOINT + '/dsh-float-window/chat', {
+                    method: 'POST',
+                    headers: { 'content-type': 'application/json' },
+                    body: JSON.stringify({ text: v }),
+                }).then((r) => r.json()).then((j) => {
+                    if (!j.ok) toast('发送失败：' + j.error)
+                }).catch((e) => toast('发送失败：' + e.message))
+            } else {
+                send({ cmd: 'chat', text: v })
+            }
+        }
+        function toast(msg) {
+            const el = document.createElement('div')
+            el.textContent = msg
+            el.style.cssText = 'position:fixed;left:8px;right:8px;bottom:44px;background:#3a2028;border:1px solid #7a2b3a;color:#ffd7de;font-size:11.5px;padding:6px 8px;border-radius:8px;z-index:40'
+            document.body.appendChild(el)
+            setTimeout(() => el.remove(), 4000)
         }
         $('send').onclick = submit
         $('input').addEventListener('keydown', (e) => {