#758 Fix condition interpolation and demo infrastructure

Fixed numeric string comparison in conditions and demo infrastructure: 1. Fixed _value_to_python_literal() in variable_resolver.py/pyx to convert numeric strings to Python int/float literals 2. Fixed activity_worker.py to pass workflow_run_id when emitting completion events 3. Added examples/ volume mount to docker-compose.yml 4. Created examples/parallel/__init__.py for proper Python package import 5. Added demo-token Makefile target for automatic JWT token generation Root cause: Recent changes to condition interpolation used repr() on all strings, causing: - '0' < 2 TypeError (string vs int comparison) - Double-quoting in 'text' in '{{stdout}}' conditions Fix: Only use repr() for numeric strings (converting to int/float), return non-numeric strings as-is.