fix: reject branch names where any path component ends with .lock

git check-ref-format forbids .lock on any component of a ref path,
not just the final segment. The previous check only tested
name.endswith(".lock"), so a name like "x.lock/y" slipped through
validation and would fail at git worktree add time with an opaque
error instead of the friendly WorktreeError.

Fix by splitting on "/" and checking every component.

Add "x.lock/y" to the parametrize list in test_validate_branch_name_rejects_bad
to cover this case explicitly.

Signed-off-by: Daiyan Alamgir <daiyan.alamgir@gmail.com>

omnigent/host/git_worktree.py

@@ -60,8 +60,8 @@ def validate_branch_name(name: str) -> None:
         raise WorktreeError(f"branch name must not start or end with '/': {name!r}")
     if name.endswith("."):
         raise WorktreeError(f"branch name must not end with '.': {name!r}")
-    if name.endswith(".lock"):
-        raise WorktreeError(f"branch name must not end with '.lock': {name!r}")
+    if any(part.endswith(".lock") for part in name.split("/")):
+        raise WorktreeError(f"branch name path components must not end with '.lock': {name!r}")
     if ".." in name:
         raise WorktreeError(f"branch name must not contain '..': {name!r}")
     if "//" in name:

tests/host/test_git_worktree.py

@@ -317,7 +317,19 @@ def test_remove_worktree_missing_path_fails(git_repo: Path) -> None:
 
 @pytest.mark.parametrize(
     "bad",
-    ["", "-leading", "a..b", "a/.hidden", "x.lock", "a b", "a~b", "a:b", "/lead", "trail/"],
+    [
+        "",
+        "-leading",
+        "a..b",
+        "a/.hidden",
+        "x.lock",
+        "x.lock/y",
+        "a b",
+        "a~b",
+        "a:b",
+        "/lead",
+        "trail/",
+    ],
 )
 def test_validate_branch_name_rejects_bad(bad: str) -> None:
     """Branch names violating git ref-format are rejected before reaching argv."""