docs(paper): revise per Codex+Grok review; pdfLaTeX; F1/F0.5 charts

Convert to pdfLaTeX + CJKutf8 (builds under the Overleaf/arXiv default engine; 微信
renders). Restore the constant-F1 iso-contour curves on the P/R plot and add the
F1/F0.5 grouped-bar figure (matching the 3-panel comparison chart).

Apply the triangulated Codex/Grok review fixes:
- scope "false-positive-zero guarantee" -> "live-row re-read exclusion invariant";
  reserve precision/FP for measured results
- add the end-to-end-recall column; footnote the fqlite 0D TP=20 vs 19-substrate
  projection artifact
- correct WAL salt behaviour (changed on WAL reset after checkpoint, not per txn)
- qualify secure_delete (ordinary b-tree tables; FTS shadow-table exception) and
  split auto_vacuum FULL vs INCREMENTAL
- relabel rollback-journal folding as journal-based (not WAL-based)
- add WITHOUT ROWID scope caveat; cite the implementation/corpus catalogue for
  reproducibility and per-asset provenance
- de-overstate ("in this harness"); trim the WeChat case; reduce AI-tells

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: h4x0r

paper/Makefile

@@ -1,14 +1,14 @@
-# Build the SQLite recovery paper (XeLaTeX + BibTeX).
+# Build the SQLite recovery paper (pdfLaTeX + BibTeX).
 PAPER = sqlite-recovery
 
 .PHONY: all clean
 all: $(PAPER).pdf
 
 $(PAPER).pdf: $(PAPER).tex $(PAPER).bib
-	xelatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
+	pdflatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
 	bibtex $(PAPER)
-	xelatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
-	xelatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
+	pdflatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
+	pdflatex -interaction=nonstopmode -halt-on-error $(PAPER).tex
 
 clean:
 	rm -f $(PAPER).aux $(PAPER).bbl $(PAPER).blg $(PAPER).log $(PAPER).out

paper/sqlite-recovery.bib

@@ -139,3 +139,11 @@ @misc{digitalcorpora_sqlite
   year         = {2026},
   note         = {Companion to \cite{nemetz2018corpus}; accessed 2026-06}
 }
+
+@misc{sqlite4n6,
+  author       = {Hui, Albert Kwun Tai},
+  title        = {{sqlite4n6}: an open {SQLite} deleted-record recovery toolkit},
+  howpublished = {\url{https://github.com/SecurityRonin/sqlite-forensic}},
+  year         = {2026},
+  note         = {Reference implementation; corpus catalogue, harness, and committed competitor setup. Accessed 2026-06}
+}