Full correctness check against the docs: safer writes, reverts and texts

Safety
- Writes are serialized (Workspace.lock): two background jobs rebuilding one
  package (a sound and its subtitle applied side by side) lost an edit.
- A store copies a bank file or package as "original" only if it matches the
  shipped catalog (Workspace.unoriginal_files: in-memory sounds, bank copies of
  voice lines, subtitles); the editor refuses to switch stores while changes
  are applied. A second store could otherwise resurrect a reverted sound.
- Mod import in the editor asks before overwriting files changed outside the
  tool (it forced silently).
- Revert all in the editor reverts texts too; the uninstaller counts text
  edits before offering to delete the store.
- ackit restore-backup: the full-backup restore decisions.md described; it
  keeps the sounds of WADs without a full copy recorded.
- build_catalog also stops when a subtitle differs from the catalog.

Languages and texts
- Game.language() returns languages without voices (JPN, RUS, ...) and
  Game.voice_archive() their INT voices; ackit text --lang JPN works.
- Menu lookups parse one cached file (find & replace: minutes -> ms).
- Subtitles decode cp1252 as Windows does: the UTF-8-in-cp1252 line
  Speech_TAPE_J_Answer_1_00 (KOR/POL/POR/RUS) is written back byte-for-byte;
  SUB_KOR/SUB_RUS rebuilt from the original game (only those rows changed).
- Mods exported while another language is loaded keep name and line.

Other fixes
- Down-mix folds extra channels in at -3 dB (a 5.1 centre voice was dropped).
- e2e_editor no longer overwrites the user's settings.json; kill_game waits
  for the game to exit before reverts.
- Recorder handles Int32/UInt8 input and split frames; package block cache
  locked; conflict messages, CLI help examples, stale docstrings and doc
  references fixed; tests no longer read this PC's game language.

Docs (decisions, user guide, README, subtitles.md, banks.md, catalog README,
REPORT, NOTES, CLAUDE.md) updated; check_docs: 102 claims match. 148 tests;
e2e_features 9/9, e2e_editor and verify PASS; game original afterwards.

ackit/verify/catalogcheck.py

@@ -399,8 +399,9 @@ def check_speakers(rep, rows, col):
 def check_menu(rep, game):
     """Menu texts: the same keys in every language (facts; differences are the game's own)."""
     from .. import loctext
-    root = os.path.join(game.root, "BmGame", "Localization")
-    if not os.path.isdir(root):
+    from ..texts import _find_dir
+    root = _find_dir(game.root, "BmGame", "Localization")       # case-insensitive (Linux)
+    if not root:
         return
     keys = {}
     for lang in loctext.languages(root):
@@ -443,7 +444,7 @@ def run(game, archives=None, quick=False, log=print, progress=None):
         check_subtitle_lines(rep, rows_all)
         check_speakers(rep, rows_all, col)
         check_menu(rep, game)
-    characters = load_characters(lang=game.language())
+    characters = load_characters(lang=game.voice_archive(game.language()))
     known = {n.lower() for s in cat.sounds for n in s.names()}
     # speaker names are the same in every language; only meaningful for the build the lists were made for
     if any(a in game.languages and is_shipped(game, a) for a in archives):