feat(render3d): gpu_vk_draw.ludic - Vulkan programs, pipelines, uniform blocks and passes

The drawing half of the Vulkan backend, compiled into render3d and not yet reached from it:

- gvk_program: a program handle as its manifest variant - two SPIR-V modules, a descriptor set
  layout (the vertex block at 0, the fragment block at 1, the samplers at their manifest bindings)
  and a pipeline layout. Nothing is compiled at run time.
- gvk_pipeline: one pipeline per program, recorded vertex layout, render state and pass formats,
  built the first time that combination draws. Attributes the shader does not read are left out;
  the front face is clockwise, since neither API flips y between clip space and its target rows.
- gvk_uniform / gvk_u_set / gvk_bind_texture: loose uniforms written into each stage's block at
  the manifest's offsets and array strides; gvk_draw_set copies the blocks into a per-frame ring
  at the device's alignment and fills a descriptor set from a per-frame pool, with a white 1x1
  texture for a sampler nothing was bound to.
- The frame: one command buffer; a framebuffer bind ends the pass and the next begins at its first
  clear or draw (a clear that comes first is the load op); attachments move to attachment layouts
  for the pass and back to SHADER_READ_ONLY after it, a cascade drawn through a view of its layer.
  gvk_present submits and waits; gvk_screenshot reads the screen image back bottom row first.

r3d.ludic now imports gpu_manifest.ludic too. Textures remember their size.

OpenGL frames byte-identical at the five viewpoints; 59 self-tests pass; VKRES OK and VKDEVICE OK.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/ludic.render3d/r3d.ludic

@@ -4,12 +4,14 @@
 # ============================================================================
 import "fmath.ludic"
 import "gpu.ludic"
+import "gpu_manifest.ludic"
 import "gpu_vk.ludic"
 import "gpu_vk_res.ludic"
 import "prof.ludic"
 import "programs.ludic"
 import "texture.ludic"
 import "mesh.ludic"
+import "gpu_vk_draw.ludic"
 import "camera.ludic"
 import "sky.ludic"
 import "daylight.ludic"