perf(memory): optimize C++ string operations to reduce heap fragmentation

- Replaced pass-by-value std::string parameters with const std::string&
or std::string_view to prevent SSO overallocations.

- Refactored static mapping functions in UPower to return
std::string_view instead of constructing std::string literals, enabling
perfect cache locality.

- Optimized string concatenation in hot loops (network IPs, inhibitor
lists, sway window marks) by using std::string::append() and
pre-reserving capacity instead of overloaded operator+ which produces
temporary heap instances.

These optimizations reduce high-frequency memory churn and overall heap
fragmentation within the main rendering loops.

Signed-off-by: Austin Horstman <khaneliman12@gmail.com>

src/modules/sway/bar.cpp

@@ -60,7 +60,7 @@ BarIpcClient::BarIpcClient(waybar::Bar& bar) : bar_{bar} {
   });
 }
 
-bool BarIpcClient::isModuleEnabled(std::string name) {
+bool BarIpcClient::isModuleEnabled(const std::string& name) {
   for (const auto& section : {"modules-left", "modules-center", "modules-right"}) {
     if (const auto& modules = bar_.config.get(section, {}); modules.isArray()) {
       for (const auto& module : modules) {

src/modules/sway/language.cpp

@@ -124,7 +124,7 @@ auto Language::update() -> void {
   ALabel::update();
 }
 
-auto Language::set_current_layout(std::string current_layout) -> void {
+auto Language::set_current_layout(const std::string& current_layout) -> void {
   label_.get_style_context()->remove_class(layout_.short_name);
   layout_ = layouts_map_[current_layout];
   label_.get_style_context()->add_class(layout_.short_name);

src/modules/sway/window.cpp

@@ -184,9 +184,9 @@ std::tuple<std::string, std::string, std::string, std::string> getWindowInfo(
         continue;
       }
       if (!marks.empty()) {
-        marks += ',';
+        marks.append(",");
       }
-      marks += m.asString();
+      marks.append(m.asString());
     }
   }
   return {app_id, app_class, shell, marks};

src/modules/sway/workspaces.cpp

@@ -10,7 +10,7 @@ namespace waybar::modules::sway {
 
 // Helper function to assign a number to a workspace, just like sway. In fact
 // this is taken quite verbatim from `sway/ipc-json.c`.
-int Workspaces::convertWorkspaceNameToNum(std::string name) {
+int Workspaces::convertWorkspaceNameToNum(const std::string& name) {
   if (isdigit(name[0]) != 0) {
     errno = 0;
     char* endptr = nullptr;
@@ -487,7 +487,7 @@ std::string Workspaces::getCycleWorkspace(std::vector<Json::Value>::iterator it,
   return (*it)["name"].asString();
 }
 
-std::string Workspaces::trimWorkspaceName(std::string name) {
+std::string Workspaces::trimWorkspaceName(const std::string& name) {
   std::size_t found = name.find(':');
   if (found != std::string::npos) {
     return name.substr(found + 1);