doc-linter: narrow argv parsing exception scope to (IndexError, SyntaxError, ValueError)

CodeRabbit / Ruff BLE001: the previous 'except Exception as e:' on the
explicit-file-list path caught any error, masking runtime failures
from handle_file_action() as silent fallback behavior. Only input
validation errors from ast.literal_eval(sys.argv[1]) should trigger
the fallback walk.

Refactor:

- Wrap only the parse step in try/except, catching just IndexError
  (missing argv[1]), SyntaxError (malformed literal), and ValueError
  (non-literal input).
- On parse failure, set files = None and dispatch to the DOCS_ROOT
  walk via an explicit 'else' branch.
- On parse success, run the file loop outside the try so any errors
  from handle_file_action() propagate normally and CI fails loudly.

Also drops the unused 'as e' (Ruff BLE001 noise) and the implicit
catch of TypeError (e.g. ast.literal_eval('42') returns an int and
'for file in 42:' would have been silently swallowed -> fallback
walk; now it raises clearly).

Verified scenarios:
- explicit file list (CI normal path) -> exit 0.
- no argv -> IndexError caught -> walks DOCS_ROOT.
- malformed argv ('not-a-list') -> SyntaxError caught -> walks DOCS_ROOT.
- explicit list with a non-existent file -> FileNotFoundError
  propagates (previously silently triggered a fallback walk).
- explicit list with a non-list literal ('42') -> TypeError
  propagates (programming error stays visible).

1 files changed, 9 insertions, 1 deletions

diff --git a/scripts/doc-linter.py b/scripts/doc-linter.py
index b1977f84..8e74600f 100644
--- a/scripts/doc-linter.py
+++ b/scripts/doc-linter.py
@@ -250,8 +250,16 @@ def main():
     """Entry point: lint the changed-file list from argv, or fall back to walking `docs/`."""
     bool_error = True
     print('start')
+    # Only the argv-parsing step is wrapped in try/except. Errors raised by
+    # handle_file_action() must propagate so CI failures stay visible instead
+    # of silently triggering a full docs/ walk.
     try:
         files = ast.literal_eval(sys.argv[1])
+    except (IndexError, SyntaxError, ValueError):
+        # No argv or malformed list -> fall back to walking DOCS_ROOT.
+        files = None
+
+    if files is not None:
         for file in files:
             if (
                 file.endswith(SUPPORTED_EXTS)
@@ -260,7 +268,7 @@ def main():
             ):
                 if handle_file_action(file) is False:
                     bool_error = False
-    except Exception as e:
+    else:
         for root, _dirs, files in os.walk(DOCS_ROOT):
             path = root.split(os.sep)
             for file in files: