H1+M2 review findings: CSV 5000x50 render cap (truncated with note) + stale output sweep; 4 regression tests (H1x3, M2x1); USER_GUIDE truncation docs

USER_GUIDE.md

@@ -28,7 +28,7 @@ Everything runs locally (or on your own server); **no file ever leaves your mach
 | TeX / LaTeX | `.tex` `.latex` | Via pandoc; needs `\documentclass` or a leading `%`, else treated as plain text |
 | Extended markup | `.org` `.adoc` `.rst` | Org mode, AsciiDoc, reStructuredText via pandoc |
 | Text | `.txt` `.log` | UTF-8 safe, paginated |
-| Data | `.csv` `.tsv` | Auto-detected delimiter → styled table; max 5000 rows × 50 cols |
+| Data | `.csv` `.tsv` | Auto-detected delimiter → styled table; **truncated to 5000 rows × 50 cols** (extra data dropped with a note; split to include more) |
 | Structured | `.json` `.xml` | Cleanly formatted listing |
 | Vector | `.svg` | Embedded via WeasyPrint |
 | Images | `.png` `.jpg` `.jpeg` `.webp` `.tiff` `.bmp` | One PDF page per image; max side 3000 px |
@@ -94,7 +94,7 @@ See `COOLIFY.md` in this directory (3 steps: Dockerfile service, port 8030, volu
 | `DRM protected` style errors | Remove DRM first (Calibre / Calibre-DB tools) — this app can't decrypt |
 | Stuck at `Working…` forever | The server restarted mid-job; refresh the page and re-upload |
 | `Unsupported format` | File isn't one of the 27 supported types — see §1 |
-| CSV/TSV rejected | Over 5000 rows or 50 columns — split the file |
+| CSV/TSV truncated | Over 5000 rows or 50 columns — automatically truncated with a note; split the file to include more |
 | PDF rejected | Encrypted/password-protected, or over 500 pages |
 
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