Implement central configuration, custom exceptions, logging utilities, Pydantic models, and Redis client for BitByLaw integration

- Added `config.py` for centralized configuration management including Sync, API, Advoware, EspoCRM, Redis, Logging, Calendar Sync, and Feature Flags.
- Created `exceptions.py` with a hierarchy of custom exceptions for integration errors, API errors, sync errors, and Redis errors.
- Developed `logging_utils.py` for a unified logging wrapper supporting structured logging and performance tracking.
- Defined Pydantic models in `models.py` for data validation of Advoware and EspoCRM entities, including sync operation models.
- Introduced `redis_client.py` for a centralized Redis client factory with connection pooling, automatic reconnection, and health checks.

services/espocrm_mapper.py

@@ -8,6 +8,16 @@ from typing import Dict, Any, Optional, List
 from datetime import datetime
 import logging
 
+from services.models import (
+    AdvowareBeteiligteCreate,
+    AdvowareBeteiligteUpdate,
+    EspoCRMBeteiligteCreate,
+    validate_beteiligte_advoware,
+    validate_beteiligte_espocrm
+)
+from services.exceptions import ValidationError
+from services.config import FEATURE_FLAGS
+
 logger = logging.getLogger(__name__)
 
 
@@ -27,6 +37,9 @@ class BeteiligteMapper:
             
         Returns:
             Dict mit Stammdaten für Advoware API (POST/PUT /api/v1/advonet/Beteiligte)
+            
+        Raises:
+            ValidationError: Bei Validierungsfehlern (wenn strict_validation aktiviert)
         """
         logger.debug(f"Mapping EspoCRM → Advoware STAMMDATEN: {espo_entity.get('id')}")
         
@@ -78,6 +91,14 @@ class BeteiligteMapper:
         
         logger.debug(f"Mapped to Advoware STAMMDATEN: name={advo_data.get('name')}, vorname={advo_data.get('vorname')}, rechtsform={advo_data.get('rechtsform')}")
         
+        # Optional: Validiere mit Pydantic wenn aktiviert
+        if FEATURE_FLAGS.strict_validation:
+            try:
+                validate_beteiligte_advoware(advo_data)
+            except ValidationError as e:
+                logger.warning(f"Validation warning: {e}")
+                # Continue anyway - validation ist optional
+        
         return advo_data
     
     @staticmethod