Silence SyntaxWarning in pdf_expect_token.py docstring (invalid escape sequences) #1339
Description
The artifact verification step prints a Python SyntaxWarning:
SyntaxWarning: invalid escape sequence '(' in scripts/pdf_expect_token.py
Cause: The docstring examples include backslashes that Python interprets as escape sequences.
Fix: Make the module docstring a raw string (r"""...""") or escape backslashes in the examples, so Python 3.12+ stops warning.
Scope: scripts/pdf_expect_token.py only. No functional behavior change.
Verification:
- Run: make verify-artifacts
- Expect: No SyntaxWarning lines from pdf_expect_token.py