Lumenwright 0.1.0

The first release. The lumenwright library and its kernel lumenwright-kernel are published on
crates.io; the lumenwright command (lumenwright-cli) is installed from the repository at
the tag v0.1.0. 0.1.0 draws Minecraft Java Edition worlds in the vanilla client's look
or path traced as Chunky traces it, on the CPU, Metal, Vulkan, DX12 and CUDA.

Added

• CJK and every other character no bitmap font covers are drawn, on signs and on text displays, from the Unifont the client reads out of the launcher's asset index (the jar's own unifont provider list is empty), cut and spaced as the client's unihex provider does. Request::unifont takes the directory (minecraft/font/include/unifont.json and the hex zip it names) and refuses a missing or unusable file by name (RequestError::Unifont), with no network. The command resolves it by --unifont, then its cache, then a SHA-1 and size verified download through the asset index unless --offline; lumenwright assets fetch-unifont fetches ahead.
• lumenwright::render(&Request): one frame of a Minecraft Java Edition world as RGBA8 pixels,
  with every input explicit (world, chunk rectangle, client jar, resource packs, camera, mode,
  backend, size, options, entity policy, sky). It resolves no jar, uses no network, writes no
  file and prints nothing; a request refused before drawing carries a RequestError.
• Quick mode: a rasterizer with the vanilla client's look, with smooth lighting, ambient
  occlusion, biome tints, cutout and translucent layers, the client's world fog, and the
  client's sky (sky disc, sunrise glow, sun, moon phases and stars) from the jar's environment
  attributes and day timeline. Block textures are read through the client's mip chains with
  trilinear, 4× anisotropic filtering (QuickOptions::mipmap_levels, --mipmap-levels).
• HQ mode: a path tracer ported from Chunky's (chunky-dev/chunky, GPL-3.0; see
  ACKNOWLEDGEMENTS.md and docs/research/chunky-parity.md): the Preetham sky; Chunky's sun
  (irradiance intensity^2.2, default intensity 1.25) with next-event estimation; Chunky's
  emitters, with an emittance per block material, quadratic emitted light, intensity 13, the
  emitter grid and its sampling strategies (--emitter-intensity, --emitter-sampling,
  --prevent-normal-emitter); one-sided block faces; diffuse bounces; Fresnel water with
  refraction; stochastic translucency; textures decoded and frames encoded with the display
  gamma 2.2, and Chunky's gamma (default), ACES and Hable filters. The sky is read through
  Chunky's sky cache (a 129 × 129 table in HSL, each channel at most 1), and the sun is drawn
  with the client's sun texture as Chunky draws it. Chunky's sky and sun hold while any part
  of the sun's disc is above the horizon; below it the sky falls to a night's 3% at the end
  of civil twilight, and a sun direction below the horizon gives no light (Lumenwright's own,
  as Chunky has no time of day). On the treehouse benchmark
  frame its 250-sample frame is as close to Chunky's converged frame as Chunky's own
  250-sample frame is.
• Backends: CPU on every core, Metal, Vulkan and DX12 through wgpu (feature gpu, on by
  default) and CUDA (feature cuda, with the PTX scripts/build-ptx.sh builds in a clone of the
  repository, found in the clone or named by LUMENWRIGHT_PTX). On the CPU, a
  request gives the same bytes for any thread count. The CUDA kernel is the path tracer
  inlined whole, in f32 alone: scripts/build-ptx.sh refuses a kernel with an f64
  instruction or a call other than a panic. An HQ frame logs its kernel time by CUDA events.
• Worlds from 1.16 onward: Anvil regions (gzip, zlib, LZ4, uncompressed), 1.16/1.17 and 1.18+
  chunk layouts, stored sky and block light, entity regions, the Overworld, the Nether and the
  End.
• Blocks from the client jar's blockstates and models, with resource packs layered on top;
  water and lava geometry; entities from 57 bundled cuboid models, plus block displays,
  paintings, item frames, mannequins and players built in code, with a hitbox box for the rest; and the
  block entities vanilla draws in code: signs and hanging signs with their text, chests,
  banners, bells, lectern and enchanting-table books, decorated pots, skulls and heads.
• The lumenwright command: render (PNG, and a linear .pfm in HQ mode), info, assets
  (find or download the client jar from Mojang, SHA-1 verified), backends and demo-world.