feat: initial login page

with separate file for future util endpoints,
also dummy sessions inteface

sessions/sessions_manager.go

@@ -0,0 +1,27 @@
+package sessions
+
+import (
+	"log"
+)
+
+type SessionData struct {
+	sessionId int64
+	roomId int64
+	personId int64
+}
+
+type SessionManagement interface {
+    Get(sessionId int64) SessionData
+	Save(roomId int64, personId int64) int64
+}
+
+type DummySM struct {}
+
+func (d DummySM)Get(sessionId int64) SessionData {
+	log.Printf("get dummy session by %d", sessionId)
+	return SessionData{}
+}
+func (d DummySM)Save(roomId int64, personId int64) int64 {
+	log.Printf("save dummy session with %d %d", roomId, personId)
+	return 1
+}