fix(index): preserve path operands when moving and checking ignores

<!-- agent -->
`IndexFile.move()` forwarded paths without an option separator in both
its preliminary dry run and its actual move. A `--force` operand could
overwrite an existing destination, and `--no-dry-run` could move files
even when the caller explicitly requested `dry_run=True`.
`Repo.ignored()` likewise interpreted leading-dash filenames as options.

Insert `--` before paths in both wrappers. The shared move argument list
protects both invocations; explicit keyword options still work. Literal
leading-dash filenames, including values containing spaces, remain usable.
Update the unreleased changelog for both APIs.

Git reference: `builtin/mv.c` and `builtin/check-ignore.c` use
`parse_options()` with `--` support at Git commit
`12cb6293d6288865c1a133cf22accbaf99d13eb6`.

Validation: all four new path regressions failed before the fix. The
positional, index, and repository suites pass 153 tests and 14 subtests,
with four skips, using test-local `init.defaultBranch=master` and
`core.quotePath=true`. One unrelated revision-parsing test was excluded:
it traverses pre-existing checkpoint refs pointing at trees. Tested with
Apple Git 2.54.0; `git diff --check` passes.

Assisted-by: GPT 6.0
Co-authored-by: GPT 6.0 <codex@openai.com>

Author: Byron

git/index/base.py

@@ -1133,6 +1133,7 @@ def move(
         args = []
         if skip_errors:
             args.append("-k")
+        args.append("--")
 
         paths = self._items_to_rela_paths(items)
         if len(paths) < 2:

git/repo/base.py

@@ -1137,7 +1137,7 @@ def ignored(self, *paths: PathLike) -> List[str]:
             Subset of those paths which are ignored
         """
         try:
-            proc: str = self.git.check_ignore(*paths)
+            proc: str = self.git.check_ignore("--", *paths)
         except GitCommandError as err:
             if err.status == 1:
                 # If return code is 1, this means none of the items in *paths are

test/test_positional_args.py

@@ -80,3 +80,41 @@ def test_remote_ref_delete_preserves_operand(tmp_path):
     with mock.patch.object(Git, "_call_process") as run:
         RemoteReference.delete(repo, ref)
     assert run.call_args[0] == ("branch", "-d", "-r", "--", ref)
+
+
+def test_move_treats_option_shaped_source_as_filename(tmp_path):
+    repo = Repo.init(tmp_path)
+    (tmp_path / "--force").write_text("literal source")
+    repo.index.add(["--force"])
+    assert repo.index.move(["--force", "destination"]) == [("--force", "destination")]
+    assert (tmp_path / "destination").read_text() == "literal source"
+    assert not (tmp_path / "--force").exists()
+
+
+def test_move_cannot_override_overwrite_protection(tmp_path):
+    repo = Repo.init(tmp_path)
+    for name in ("--force", "source", "destination"):
+        (tmp_path / name).write_text(name)
+    repo.index.add(["--force", "source", "destination"])
+    with pytest.raises(GitCommandError):
+        repo.index.move(["--force", "source", "destination"])
+    assert (tmp_path / "source").read_text() == "source"
+    assert (tmp_path / "destination").read_text() == "destination"
+    repo.index.move(["source", "destination"], force=True)
+    assert (tmp_path / "destination").read_text() == "source"
+
+
+def test_ignored_treats_option_shaped_path_as_filename(tmp_path):
+    repo = Repo.init(tmp_path)
+    (tmp_path / ".gitignore").write_text("--verbose\n--arg value\n")
+    assert repo.ignored("--verbose", "--arg value") == ["--verbose", "--arg value"]
+
+
+def test_move_cannot_override_dry_run(tmp_path):
+    repo = Repo.init(tmp_path)
+    (tmp_path / "source").write_text("source")
+    repo.index.add(["source"])
+    with pytest.raises(GitCommandError):
+        repo.index.move(["--no-dry-run", "source", "destination"], dry_run=True)
+    assert (tmp_path / "source").read_text() == "source"
+    assert not (tmp_path / "destination").exists()