fix(extensions/git): pass script path to core.get_repo_root for cwd-outside-repo callers

Without script_file, core.get_repo_root() falls back to Path.cwd() when
SPECIFY_INIT_DIR is unset and no .specify root is found upward — the
bash twin instead falls back to the script's install location
(.specify/scripts/...). Pass script_file so both twins resolve the
same repo_root; TypeError fallback keeps older cores working.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: marcelsafin

extensions/git/scripts/python/create_new_feature_branch.py

@@ -435,7 +435,13 @@ def main(argv: list[str]) -> int:
         return 1
 
     if core is not None and hasattr(core, "get_repo_root"):
-        repo_root = core.get_repo_root()
+        # Pass script path so cwd-outside-repo callers land on the same
+        # fallback the bash twin does. Older cores don't accept the kwarg —
+        # fall back to the no-arg call for compatibility.
+        try:
+            repo_root = core.get_repo_root(script_file=Path(__file__))
+        except TypeError:
+            repo_root = core.get_repo_root()
     else:
         toplevel = _git_lines(Path.cwd(), "rev-parse", "--show-toplevel")
         if toplevel: