perf(agc): baseline shader recompilation on registration
In main, baseline recompilation depends on the resource configuration and runs on the first use of each corresponding variant.
This branch prepares IR, the static interface, baseline SPIR-V, and available ABI variants during shader registration. The compiled artifact is separate from per-draw and per-dispatch data.
Before the first execution with a new resource configuration, the runtime reads descriptors, validates compatibility, prepares the binding plan, specializes existing SPIR-V by substituting constants and removing unused branches and computations, materializes invocation data, and creates the Vulkan pipeline. These results are cached.
Variants that depend on linked graphics stages are prepared when the corresponding ABI is resolved. Unregistered compute shaders undergo baseline preparation on their first dispatch, emit an error log, and cache the result.
Subsequent executions reuse prepared artifacts, specializations, and pipelines while updating invocation data and resources as needed.