Add colors::kTooltipGold to ui_colors.hpp and replace 14 inline
ImVec4(1.0f, 0.82f, 0.0f, 1.0f) literals in inventory_screen.cpp
for item set names, unique markers, and quest item indicators.
Add getInventorySlotName() and renderBindingType() to ui_colors.hpp,
replacing 3 copies of the 26-case slot name switch (2 inventory_screen
+ 1 game_screen) and 2 copies of the binding type switch. Removes ~80
lines of duplicate tooltip code.
Add renderCoinsFromCopper(uint64_t) overload in ui_colors.hpp that
decomposes copper into gold/silver/copper and renders. Replace 14
manual 3-line decomposition blocks across game_screen and
inventory_screen with single-line calls.
Create shared include/ui/ui_colors.hpp with common ImGui color constants,
item quality color lookup, and renderCoinsText utility. Remove 3 duplicate
renderCoinsText implementations and 3 duplicate quality color switch
blocks across game_screen, inventory_screen, and quest_log_screen.
