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/cffi.cpp

@@ -71,6 +71,7 @@ CFFI::CFFI(const std::string& name, const std::string& id, const Json::Value& co
 
   // Prepare config_entries array
   std::vector<ffi::wbcffi_config_entry> config_entries;
+  config_entries.reserve(keys.size());
   for (size_t i = 0; i < keys.size(); i++) {
     config_entries.push_back({keys[i].c_str(), config_entries_stringstor[i].c_str()});
   }