Loot filter on the options window's Beute page

Per category (Gold, Tränke, white/blue/yellow/brown/green items) one of
Löschen (loot deleted at once), Ignorieren (pickup key leaves it), Standard,
Immer anzeigen (label without the labels key). Replaces the game's
PICKUPAUTO choice; settings in [loot] of sacredK.ini. docs/loot-filter.md.
Also ignore MSYS *.stackdump files.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

CMakeLists.txt

@@ -69,6 +69,7 @@ add_library(sacredK SHARED
     src/mods/guards.cpp
     src/mods/charexport.cpp
     src/mods/options.cpp
+    src/mods/lootfilter.cpp
 )
 target_include_directories(sacredK PRIVATE src)
 target_compile_options(sacredK PRIVATE ${SACREDK_CXX_FLAGS})