Add Saxony SächsBeamtVG acceptance case (first non-Bavarian Landesrecht)

Complete the first §-structured Landesrecht acceptance case for wave six: the
Saxon Civil Servants' Pension Act (SächsBeamtVG) in its 1 Feb 2025 version plus
the amending act of 13 April 2026 (SächsGVBl. S. 134). All five commands are
recognised and applied without residue — the amount replacements in § 47 and the
re-enactment of § 80(1) sentence 2.

- LandesRechtTextParser: recognise arabic, keyword-first structural headings
  ("Abschnitt 1", "Unterabschnitt 2", "Teil 3") via GLIEDERUNG_ARABISCH, in
  addition to Bavaria's roman "I. Abschnitt" form. Bavaria behaviour unchanged.
- TextBereiniger: strip the footer of revosax full-text output (REVOSAX_FUSS,
  "https://…revosax… Fassung vom … Seite N von M").
- Add the consolidated pre-amendment stem as canonical plaintext
  (sampledata/Sachsen/SaechsBeamtVG-alt.txt, derived from the archived revosax
  full text) and EndToEndTest.saechsBeamtVgAcceptance (5 applied, 0 manual).

220 tests green; federal and Bavarian pinned numbers unchanged.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Change-Id: I8e878bc9506f24028cf643a873de000f3d066d64
6 files changed
tree: cfc08069f1da4bff2c8f1b67de85e70defad2fa2
  1. .mvn/
  2. src/
  3. .gitignore
  4. COPYING
  5. FASSUNGEN.txt
  6. mvnw
  7. mvnw.cmd
  8. pom.xml
  9. README.adoc