ludic/changes/r3d-fault-loud.md

bump: minor type: fix A renderer that cannot draw says so and stops. A LUDIC_HOME handed over with its ~ unexpanded (env LUDIC_HOME=~/x) left render3d without its shaders: "vulkan cannot start" was printed, and the run went on, logging "no SPIR-V variant" for every program - a world with no terrain, shadows or impostors. Now r3d_home puts a leading ~ under $HOME; the SPIR-V manifest ends with E <count> (written by ludic-dev shaders) and one without it, or miscounted, is refused; and every such failure is a fault (gpu_fault.ludic): r3d_open and each r3d_load_step return false on one, a program with no variant is listed, and a game asks r3d_fault() and ends with r3d_fault_exit(code), which prints the reason and every missing program. tests/manifest_test.ludic holds the parse, the refusals, r3d_tilde and that every program in variants.list resolves in the shipped manifest.