Phase A/B: fix the game loop and trim the asset payload

Phase A (the hard blocker): the engine now plays a real table live in
the browser via a real per-frame game loop, not just a static render.

Two real, previously-unknown upstream bugs found and fixed along the way:
- RenderDevice::WaitForVSync() unconditionally spawned a real std::thread
  every frame, even on __STANDALONE__ builds - a hard crash under
  Emscripten's single-threaded runtime (0003).
- The desktop game loop is a blocking native while loop with manual
  uSleep throttling, incompatible with a single-threaded WASM main
  thread. Adds Player::EmscriptenStepFrame() (one frame, no internal
  loop) driven by emscripten_set_main_loop, plus new JS-callable
  lifecycle entry points (vpinball_wasm_start/stop/dispose in the new
  src/core/EmscriptenBridge.cpp) that bypass the desktop main()/WinMain()
  chain entirely, since that chain assumes the process runs exactly one
  table to completion then exits (0004).

Verified end-to-end in Chrome: real .vpx load, real shader compilation,
real physics/script engine init, a real running frame loop (observed
advancing), and a clean stop() -> ~Player() teardown mid-session with
no crash or hang.

Phase B: trims the preloaded asset payload from ~51MB to ~11MB by
excluding editor-only bundled example tables and a Monaco code editor
never used by the player runtime, and adds real link-time optimization
(-O2 --closure 1) and --use-preload-cache for repeat visits.

patches/vpinball/0001-emscripten-cmake-target.patch

@@ -1,5 +1,5 @@
 diff --git a/CMakeLists.txt b/CMakeLists.txt
-index 1fcf242..f9338b2 100644
+index 1fcf242..bc8f7ff 100644
 --- a/CMakeLists.txt
 +++ b/CMakeLists.txt
 @@ -50,6 +50,7 @@ set(_vpx_valid_combos
@@ -10,7 +10,7 @@ index 1fcf242..f9338b2 100644
     DX9-windows)
  if(NOT "${RENDERER}-${PLATFORM}" IN_LIST _vpx_valid_combos)
     string(REPLACE ";" "\n  " _vpx_available "${_vpx_valid_combos}")
-@@ -784,6 +785,123 @@ elseif(PLATFORM STREQUAL "linux")
+@@ -784,6 +785,124 @@ elseif(PLATFORM STREQUAL "linux")
        endif()
     endif()
  
@@ -41,6 +41,7 @@ index 1fcf242..f9338b2 100644
 +
 +   add_executable(vpinball
 +      ${VPX_STANDALONE_SOURCES}
++      ${CMAKE_SOURCE_DIR}/src/core/EmscriptenBridge.cpp
 +   )
 +
 +   target_include_directories(vpinball PUBLIC
@@ -134,7 +135,7 @@ index 1fcf242..f9338b2 100644
  # iOS and Android libvpinball build
  
  elseif(PLATFORM STREQUAL "ios" OR PLATFORM STREQUAL "ios-simulator" OR PLATFORM STREQUAL "android")
-@@ -957,4 +1075,9 @@ elseif(PLATFORM STREQUAL "ios" OR PLATFORM STREQUAL "ios-simulator" OR PLATFORM
+@@ -957,4 +1076,9 @@ elseif(PLATFORM STREQUAL "ios" OR PLATFORM STREQUAL "ios-simulator" OR PLATFORM
  
  endif()