change: Add error context handling

[mathysgrapotte]

Is your change request related to a problem? Please describe.

Current errors lack operational context needed to debug pipeline failures.

Describe the solution you'd like

1. Add BaseComponent._error() helper method
2. Implement context managers for file operations
3. Enforce error context in data handlers/loaders including:
   • Component name
   • Config snapshot
   • Input metadata

[mathysgrapotte]

example implementation for context :

from typing import Dict, Any, Type
from stimulus.exceptions import StimulusError

class BaseComponent:
    """Base class providing error context handling"""
    
    def __init__(self, config: Dict[str, Any]):
        self.config = config
        
    def _component_context(self) -> Dict[str, Any]:
        return {
            "component": self.__class__.__name__,
            "config_keys": list(self.config.keys()),
            "phase": getattr(self, "current_phase", "initialization")
        }
    
    def error(self, exc_type: Type[StimulusError], msg: str, **ctx) -> StimulusError:
        return exc_type(msg).add_context(
            **self._component_context(),
            **ctx
        )

# Usage in data handler
class ImageHandler(BaseComponent):
    def load(self, path: str):
        if not path.endswith(".png"):
            raise self.error(
                StimulusError,
                "Unsupported image format",
                allowed_formats=[".png", ".jpg"],
                requested_file=path
            )