Add bootstrap step for machines without conda or the upstream clone

SETUP.md sent a fresh machine straight to setup_env.sh, which calls conda and
builds inside ~/sum-parts. Neither exists on a clean box, so the first command
failed. This repo only carries our scripts; the benchmark itself is a separate
clone.

bootstrap.sh installs miniconda into $HOME (no sudo), clones
tudelft3d/SUM-Parts-Benchmarks, and reports whether the GPU has room for the
paper's voxel_max=64000 (~16.5 GB). Idempotent - an existing install or clone
is reported and left alone.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.gitattributes

@@ -0,0 +1,14 @@
+# Shell scripts and python run inside WSL/Linux. Checking them out with CRLF
+# breaks them at the first line: `bash: $'\r': command not found`.
+# Force LF regardless of the platform doing the checkout.
+*.sh   text eol=lf
+*.py   text eol=lf
+*.yaml text eol=lf
+*.yml  text eol=lf
+
+*.md   text
+*.html text
+
+*.ply  binary
+*.obj  binary
+*.pth  binary