fix(classification): restore service logic and standardization formula

- Restored missing method implementations in ClassificationService (classify, extract_metrics)
- Fixed Standardization Logic not being applied in metric cascade
- Bumped version to v0.7.4 in config.py
- Removed duplicate API endpoint in app.py
- Updated MIGRATION_PLAN.md

company-explorer/backend/config.py

@@ -10,7 +10,7 @@ try:
     class Settings(BaseSettings):
         # App Info
         APP_NAME: str = "Company Explorer"
-        VERSION: str = "0.6.4"
+        VERSION: str = "0.7.3"
         DEBUG: bool = True
         
         # Database (FINAL CORRECT PATH for Docker Container)
@@ -34,7 +34,7 @@ except ImportError:
     # Fallback wenn pydantic-settings nicht installiert ist
     class FallbackSettings:
         APP_NAME = "Company Explorer"
-        VERSION = "0.6.4"
+        VERSION = "0.7.3"
         DEBUG = True
         DATABASE_URL = "sqlite:////app/companies_v3_fixed_2.db" # FINAL CORRECT PATH
         GEMINI_API_KEY = os.getenv("GEMINI_API_KEY")