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/loctext.py

@@ -64,6 +64,21 @@ def parse(raw, lang, fname):
     return out
 
 
+def encoding(raw):
+    """Encoding of a file's bytes: 'utf-16', 'utf-8' or 'cp1252'."""
+    return "utf-16" if raw[:2] == b"\xff\xfe" else "utf-8" if raw[:3] == b"\xef\xbb\xbf" else "cp1252"
+
+
+def check_value(value, enc, fname):
+    """Raise TextError if `value` cannot be written into a file of encoding `enc` (what `write` refuses)."""
+    if "\r" in value or "\n" in value:
+        raise TextError("a menu text cannot contain line breaks (use the game's own markers, e.g. \\n)")
+    try:
+        _encode(value, enc)
+    except UnicodeEncodeError:
+        raise TextError("%s is stored as %s and cannot hold these characters" % (fname, enc)) from None
+
+
 def write(raw, lang, fname, values):
     """New file bytes with {entry key: new value} applied (keys not in the file raise TextError)."""
     text, enc = _decode(raw)
@@ -73,8 +88,7 @@ def write(raw, lang, fname, values):
         e = by_key.get(key)
         if e is None:
             raise TextError("no text %s in %s" % (key, fname))
-        if "\r" in value or "\n" in value:
-            raise TextError("a menu text cannot contain line breaks (use the game's own markers, e.g. \\n)")
+        check_value(value, enc, fname)
         line = lines[e.line]
         end = line[len(line.rstrip("\r\n")):]
         head = line[:line.index("=") + 1]