Add mcrf-init.sh: game project scaffolding without engine recompilation

New workflow for game developers: run mcrf-init to create a project
directory with symlinks to a pre-built engine, then just write Python
scripts and assets. Games package for distribution (Linux/Windows/WASM)
without ever rebuilding the engine.

mcrf-init.sh creates:
- build/ with symlinked binary and libs, game content in assets/ + scripts/
- build-windows/ (if engine has a Windows build)
- Makefile with run, wasm, dist-linux, dist-windows, dist-wasm targets
- Starter game.py, .gitignore, pyrightconfig.json, VERSION file

CMakeLists.txt: WASM preload paths (assets, scripts) are now
configurable via MCRF_ASSETS_DIR / MCRF_SCRIPTS_DIR cache variables,
so game project Makefiles can point WASM builds at their own content
without modifying the engine.

Also adds pyrightconfig.json for the engine repo itself (IDE support
via stubs/).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CMakeLists.txt

@@ -266,6 +266,11 @@ if(MCRF_SDL2)
     target_compile_definitions(mcrogueface PRIVATE MCRF_SDL2)
 endif()
 
+# Asset/script directories for WASM preloading (game projects override these)
+set(MCRF_ASSETS_DIR "${CMAKE_SOURCE_DIR}/assets" CACHE PATH "Assets directory for WASM preloading")
+set(MCRF_SCRIPTS_DIR "${CMAKE_SOURCE_DIR}/src/scripts" CACHE PATH "Scripts directory for WASM preloading")
+set(MCRF_SCRIPTS_PLAYGROUND_DIR "${CMAKE_SOURCE_DIR}/src/scripts_playground" CACHE PATH "Playground scripts for WASM")
+
 # Emscripten-specific link options (use ports for zlib, bzip2, sqlite3)
 if(EMSCRIPTEN)
     # Base Emscripten options
@@ -287,9 +292,9 @@ if(EMSCRIPTEN)
         # Preload Python stdlib into virtual filesystem at /lib/python3.14
         --preload-file=${CMAKE_SOURCE_DIR}/wasm_stdlib/lib@/lib
         # Preload game scripts into /scripts (use playground scripts if MCRF_PLAYGROUND is set)
-        --preload-file=${CMAKE_SOURCE_DIR}/src/$<IF:$<BOOL:${MCRF_PLAYGROUND}>,scripts_playground,scripts>@/scripts
+        --preload-file=$<IF:$<BOOL:${MCRF_PLAYGROUND}>,${MCRF_SCRIPTS_PLAYGROUND_DIR},${MCRF_SCRIPTS_DIR}>@/scripts
         # Preload assets
-        --preload-file=${CMAKE_SOURCE_DIR}/assets@/assets
+        --preload-file=${MCRF_ASSETS_DIR}@/assets
         # Use custom HTML shell - game shell (fullscreen) or playground shell (REPL)
         --shell-file=${CMAKE_SOURCE_DIR}/src/$<IF:$<BOOL:${MCRF_GAME_SHELL}>,shell_game.html,shell.html>
         # Pre-JS to fix browser zoom causing undefined values in events