Refuse loads and renders that would not fit in memory

Opening a project of ninety 17 MP photos got Effector killed by the
kernel's OOM killer: 4.6 GB of decoded RGB on a machine with 3.6 GB free,
and no core dump to show for it. Bulk allocations are now sized first and
refused with an OutOfMemoryError past three quarters of the free memory
(MemAvailable, or less under a cgroup memory.max). loadImages sizes the
batch from the file headers and refuses it before decoding anything, and
holds the decodes in flight to what is left; renderChain and renderFrames
refuse a canvas at 24 bytes a pixel, plus any picture a Path param loads.
The interface keeps a refused batch's paths, so saving the project never
drops them. Version 0.6.1.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.20)
-project(effector VERSION 0.6.0 LANGUAGES CXX)
+project(effector VERSION 0.6.1 LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
@@ -35,6 +35,7 @@ add_library(effector_core STATIC
     src/core/chain.cpp
     src/core/effect.cpp
     src/core/image.cpp
+    src/core/memory.cpp
     src/core/params.cpp
     src/core/project.cpp
     src/core/registry.cpp