v0.5.0 — scaling to large image sets (split-merge tiling)

v0.5.0 — scaling to large image sets (split-merge tiling)

Split-merge spatial tiling for sets that exceed the single-machine RAM wall:
cameras partitioned into overlapping spatial tiles, each run through the full
dense chain independently, then the per-tile meshes/clouds merged back. Enabled
by a streaming, memory-flat multi-view blend (top-K view selection streamed in
one pass; view-major bake keeps at most one source image resident), so peak RSS
is governed by mesh/atlas size, not the image count. Auto-scaling of
matcher/mapper/densify for large sets and a dense worker-thread cap.