feat: About dialog with version, commit, build time and settings path

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/layout_store.cpp

@@ -31,14 +31,6 @@ std::string sanitize(const std::string& host) {
   return out.empty() ? "_" : out;
 }
 
-std::string config_dir() {
-  const char* xdg = std::getenv("XDG_CONFIG_HOME");
-  if (xdg != nullptr && xdg[0] != '\0') return std::string(xdg) + "/udpscope";
-  const char* home = std::getenv("HOME");
-  if (home == nullptr || home[0] == '\0') return "/tmp/udpscope-config";
-  return std::string(home) + "/.config/udpscope";
-}
-
 void mkdirs(const std::string& path) {
   // **Every** component, the last one included. The condition used to be "the path has a trailing
   // slash", so the final directory was never created: `~/.config/udpscope` did not exist, the
@@ -114,6 +106,14 @@ bool parse_string_array(const std::string& in, std::vector<std::string>& out) {
 
 }  // namespace
 
+std::string config_dir() {
+  const char* xdg = std::getenv("XDG_CONFIG_HOME");
+  if (xdg != nullptr && xdg[0] != '\0') return std::string(xdg) + "/udpscope";
+  const char* home = std::getenv("HOME");
+  if (home == nullptr || home[0] == '\0') return "/tmp/udpscope-config";
+  return std::string(home) + "/.config/udpscope";
+}
+
 std::string layout_path(const std::string& host, std::uint16_t port) {
   const std::string dir = config_dir();
   mkdirs(dir);