Completes the oracle GPU surface. The reliable gap finder is
  comm -23 <(ImageDtt gpuQuad.* calls) <(GpuQuadJna overrides)
not the gpuTrace dump (only ~14 methods are instrumented, so e.g.
getFlatTextures was invisible in the trace though it is on the path).

Overrides (delegating to the new tp_proc_* texture API):
- execTextures: builds weights[3]/params[5], forwards calc_textures/calc_extra/
  linescan/dust/keep flags. Implements the production (USE_DS_DP) behavior.
- getTextureIndices: reads kernel-built count + packed indices.
- getExtra: reshapes diff_rgb_combo (texture_indices order) into
  [num_cams*(num_colors+1)][tilesX*tilesY] keyed by ntile -- identical to base.
- getFlatTextures: de-pitches gpu_textures -- identical to base.

TpJna.java: bindings for tp_proc_exec_textures/get_texture_indices/
get_diff_rgb_combo/get_textures.

Edits only -- not mvn-compiled (Eyesis run was live). Signatures match base
@Override; referenced fields are public final / public static.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>