Add redact doc pages; update timeline docs to remove GPU references

- New: redact-about.php, redact-guide.php, redact-tech.php with full
  two-pass pipeline docs, regional rule sets, output format comparison
- New: translations/redact-{about,guide,tech}.php (en + no)
- redact.php: add About/Guide/How-it-works doc links
- timeline-guide.php: remove GPU/cuttlefish engine row
- timeline-tech.php: remove GPU row, replace fine-tuned LLM section
  with SSE streaming + DOCX export section, stat4 3→2 engines
- timeline-about.php: replace dbn-legal-agent spotlight with
  SSE/DOCX export highlight
- translations/timeline-{about,guide,tech}.php: remove all GPU/
  cuttlefish references across all 4 languages; add stream_* and
  export_* keys; fix upload copy (5 files → 1 file)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

timeline-guide.php

@@ -118,11 +118,6 @@ $t   = $_pt[$uiLang] ?? $_pt['en'];
                     <td><?= htmlspecialchars($t['eng2_speed']) ?></td>
                     <td><?= htmlspecialchars($t['eng2_best']) ?></td>
                 </tr>
-                <tr>
-                    <td>GPU / cuttlefish</td>
-                    <td><?= htmlspecialchars($t['eng3_speed']) ?></td>
-                    <td><?= htmlspecialchars($t['eng3_best']) ?></td>
-                </tr>
             </tbody>
         </table>
     </div>