server: Go 服务器（REST+WSS 网关+JWT+Argon2+配对+素材直链+任务状态机）；修复并发下线 send-on-closed-channel、下发查询 SQL 优先级、配对码原子占用、上传体积上限、JWT 默认密钥告警

server/internal/ws/hub_test.go

@@ -0,0 +1,44 @@
+package ws
+
+import (
+	"testing"
+)
+
+// TestConnSendAfterClose 验证：连接关闭后 sendRaw/sendEnvelope 不 panic（回归 send-on-closed-channel）。
+func TestConnSendAfterClose(t *testing.T) {
+	c := &Conn{ID: "1", send: make(chan []byte, 1), Kind: "agent"}
+	c.close()
+	// 已关闭，发送应返回 false 而非 panic
+	if c.sendRaw([]byte("x"), true) {
+		t.Fatal("send to closed conn should return false")
+	}
+	if c.sendRaw([]byte("x"), false) {
+		t.Fatal("send to closed conn (drop) should return false")
+	}
+}
+
+// TestConnDoubleClose 双重 close 不应 panic（closeOnce 保护）
+func TestConnDoubleClose(t *testing.T) {
+	c := &Conn{ID: "1", send: make(chan []byte, 1)}
+	c.close()
+	c.close() // 第二次应无效果
+}
+
+// TestRegisterReplaceOld 同设备重连替换旧连接：旧连接被 close，映射指向新连接，且不 panic
+func TestRegisterReplace(t *testing.T) {
+	h := NewHub()
+	old := &Conn{ID: "7", send: make(chan []byte, 64)}
+	newc := &Conn{ID: "7", send: make(chan []byte, 64)}
+	h.RegisterAgent(old)
+	h.RegisterAgent(newc)
+	if !h.AgentOnline(7) {
+		t.Fatal("device 7 should be online via new conn")
+	}
+	h.UnregisterAgent(old) // 注销旧连接不应影响新连接
+	if !h.AgentOnline(7) {
+		t.Fatal("device 7 should still be online after old conn unregister")
+	}
+	if old.sendRaw([]byte("x"), false) {
+		t.Fatal("old conn should be closed")
+	}
+}