docs(writeup): NeurIPS-workshop paper skeleton + tectonic compile recipe

Minimal LaTeX skeleton: outline + evidence tables (route2 n=3 deploy numbers
filled with provenance, vanilla pending jobs 74/84) + figures + verified refs
+ appendix (4-mode traces, 6/6/6/6 partition counts, pseudocode). Build
artifacts and figs symlinks gitignored. `just paper` compiles via tectonic;
`just paper-qc` dumps text + greps for unresolved refs / TODOs.

Co-Authored-By: Claudypoo <288921227+claudypoo@users.noreply.github.com>

docs/writeup/.gitignore

@@ -0,0 +1,17 @@
+# LaTeX / tectonic build artifacts -- regenerable, never commit.
+*.pdf
+*.aux
+*.log
+*.bbl
+*.blg
+*.out
+*.fls
+*.fdb_latexmk
+*.synctex.gz
+*.toc
+build/
+# figures are symlinks into out/figs/ (regenerated by `just dyn`); don't commit.
+figs/
+# QC text dump
+paper.txt
+qc_report.txt