feat(webui): add sessions expiration

Closes #28

pkg/model/session.go

@@ -17,6 +17,6 @@ type Session struct {
 }
 
 func (session *Session) IsExpired() bool {
-	// TODO
-	return false
+	expires := session.Created.Add(12 * time.Hour) // 12 hours sessions
+	return time.Now().After(expires)
 }

pkg/webui/login.go

@@ -86,7 +86,7 @@ func handleLoginPOST(db *database.DB) http.Handler {
 			Value:    sessionId,
 			Quoted:   false,
 			Path:     "/",
-			MaxAge:   8 * 3600, // 1 hour sessions
+			MaxAge:   12 * 3600, // 12 hours sessions
 			HttpOnly: true,
 			SameSite: http.SameSiteStrictMode,
 			Secure:   true,