inflate in a caller-owned context, and a PNG decoded in three steps (parked: the boot's PNGs move to build time)

runtime/native/inflate.ludic: ZInflate holds the bit reader, the RFC tables and every table and scratch
list a block builds, made once (z_inflate_new) and rebuilt in place - an inflate allocates nothing, and a
thread that inflates holds a context of its own. RtInflateState keeps one, so z_inflate / z_uncompress /
z_gunzip and their callers are unchanged; z_*_in take the context.
render3d png_jobs.ludic: png_parse (reads, walks the chunks, makes every buffer), png_work (inflates,
unfilters, packs; makes nothing, touches no state), png_take (frees, sets tex_*); tex_prefetch runs
png_work over a list on every core through Job.parallel_for and png_decode takes a waiting result, so
what uploads and in what order is unchanged. Nothing calls tex_prefetch yet. Compiles with the game.

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

packages/ludic.render3d/env.ludic

@@ -880,6 +880,8 @@ export state Render3dState {
   tex_channels: int = 0
   tex_depth: int = 0        # bits per sample (8 or 16)
   tex_file_len: int = 0
+  tex_pf: []PngJob = null        # what tex_prefetch decoded, for png_decode to take (png_jobs.ludic)
+  tex_zs: []ZInflate = null      # an inflate context per concurrent decode, made on this thread
   tex_anisotropy: fixed = 16.0
   tex_size_ws: []int = new []int
   tex_size_hs: []int = new []int