render3d: 671 frame-reachable allocation sites to 161 - declared, split, or made nothing

@alloc_ok with its reason on what is made once per resource and kept (textures, programs, samplers,
views, layouts, memory blocks, the pipeline cache in gvk_pipe_build), on resize and swapchain
remakes, on screenshots and dumps, on a world being set up (streams, layers, water, post, bakes), on
loads (gltf_load, skin_load, tex_load*, png_decode, fonts) and on R3D_PROF / drawstats.
gltf_cached's hit path is its own and makes nothing; the miss (gltf_cached_load) is declared.
m4_look_at (now over m4_look_at_xyz) and m4_inverse work on scalars, and cam_update makes no scratch.
Left: lazy first-use starts, error and debug prints, and scratch made and freed each call (churn,
plan 25.3). Compiled (steady, and ludic deps over the game).

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

packages/ludic.render3d/texture_dds.ludic

@@ -18,6 +18,7 @@ function dds_path_of(path: string) -> string {
 }
 
 # Load the .dds at `path` as a texture (srgb: colour, sampled as sRGB), or 0
+@alloc_ok("loading a model, a texture or a font: a load, not a frame (a guest loading a teammate's look is one)")
 function tex_load_dds(render3d_st: mut Render3dState, path: string, srgb: bool) -> int {
   let b = Fs.read_bytes(path)
   if b == null { return 0 }