testfiles: real documents get short names and a source table, personal data is replaced by same-length filler (#203)

Adds the nineteen real documents under testfiles/ (mail, Office, PDF, ZIP) with short ASCII names. Recipient addresses, names, host names, mailbox identifiers and recipient-bound tokens are replaced by filler of the same length, and the archive is rebuilt from the sanitized members. test_raw_derive_testfiles.py now compares the sheet TSVs too (with a direct test on _texts()), and a real workbook carries a formula needle that only a .formulas.tsv holds. testfiles/README.md gains the provenance table and the two new rules.

Files changed:
- CHANGES.md
- VERSION
- testfiles/README.md
- testfiles/mail/github-outlook.msg
- testfiles/mail/github-roundcube.eml
- testfiles/mail/gog-outlook.msg
- testfiles/mail/gog-roundcube.eml
- testfiles/mail/tldr-outlook.msg
- testfiles/mail/tldr-roundcube.eml
- testfiles/office/excel-artificial.xlsx
- testfiles/office/excel-business.xlsx
- testfiles/office/excel-business.xlsx.expect
- testfiles/office/excel-science.xlsx
- testfiles/office/pptx-baseline.pptx
- testfiles/office/pptx-master.pptx
- testfiles/office/pptx-objects.pptx
- testfiles/office/word-complex.docx
- testfiles/office/word-simple.docx
- testfiles/pdf/einstein-dissertation.pdf
- testfiles/pdf/ifg.pdf
- testfiles/pdf/nist-ai-rmf.pdf
- testfiles/pdf/nist-ssdf-genai.pdf
- testfiles/zip/archive.zip
- tools/chemenu/tests/test_raw_derive_testfiles.py

Co-Authored-By: Claude Code <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SnAJ7Z3CpVD3PRbN73QtU2

testfiles/office/excel-business.xlsx.expect

@@ -0,0 +1,2 @@
+# the bare formula text: it is in a .formulas.tsv only, not in derived.md and not in a cell TSV
+SUM(Sales!L6:L29)