#468 Performance: Regex compiled on every call in operators.py and variable_resolver.py

Multiple hot-path functions compile regex patterns on every call instead of once: 1. engine/interpreters/operators.py:1137 - wait operation pattern 2. engine/interpreters/variable_resolver.py:207,240 - interpolation patterns FIX: Pre-compile regex patterns at module level as constants: ```python _WAIT_PATTERN = re.compile(r'...') # Module level def function(): match = _WAIT_PATTERN.match(...) # Reuse compiled ```