perf(memory): eliminate deep copies in range-based for loops and lambdas

This commit addresses memory churn caused by implicit deep copies during traversal and allocation of complex structures:

- Replaced pass-by-value 'Json::Value' in std::ranges and range-based for loops with 'const auto&' or 'const Json::Value&' in Hyprland modules, preventing large JSON tree duplications on every update.

- Fixed implicit string and pair copies in UPower and CPU Frequency loops by converting 'auto' to 'const auto&' where possible.

- Added 'std::vector::reserve' calls before 'push_back' loops in MPRIS, Niri, and CFFI modules to prevent exponential vector reallocation during initialization.

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

src/modules/hyprland/workspace.cpp

@@ -96,7 +96,7 @@ bool Workspace::handleClicked(GdkEventButton* bt) const {
 
 void Workspace::initializeWindowMap(const Json::Value& clients_data) {
   m_windowMap.clear();
-  for (auto client : clients_data) {
+  for (const auto& client : clients_data) {
     if (client["workspace"]["id"].asInt() == id()) {
       insertWindow({client});
     }