chore: add black formatting and autoflake cleanup to build pipeline and remove redundant pass statements

- Add black and autoflake invocations to the build target in Makefile for automated code formatting and unused import/variable removal
- Remove three redundant `pass` statements from abstract method bodies in ProcessHandler class, as abstract methods with docstrings do not require them

pr/tools/process_handlers.py

@@ -14,11 +14,9 @@ class ProcessHandler(ABC):
     @abstractmethod
     def get_process_type(self):
         """Return the process type this handler manages."""
-        pass
 
     def update_state(self, output):
         """Update internal state based on output."""
-        pass
 
     def get_prompt_suggestions(self):
         """Return suggested responses for current state."""