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/app.py

@@ -342,47 +342,6 @@ def override_impressum(company_id: int, url: str, background_tasks: BackgroundTa
     db.commit()
     return {"status": "updated"}
 
-@app.get("/api/companies/export")
-def export_companies_csv(db: Session = Depends(get_db)):
-    """
-    Exports a CSV of all companies with their key metrics.
-    """
-    import io
-    import csv
-    from fastapi.responses import StreamingResponse
-
-    output = io.StringIO()
-    writer = csv.writer(output)
-
-    # Header
-    writer.writerow([
-        "ID", "Name", "Website", "City", "Country", "AI Industry",
-        "Metric Name", "Metric Value", "Metric Unit", "Standardized Value (m2)",
-        "Source", "Source URL", "Confidence", "Proof Text"
-    ])
-
-    companies = db.query(Company).order_by(Company.name.asc()).all()
-
-    for c in companies:
-        writer.writerow([
-            c.id, c.name, c.website, c.city, c.country, c.industry_ai,
-            c.calculated_metric_name,
-            c.calculated_metric_value,
-            c.calculated_metric_unit,
-            c.standardized_metric_value,
-            c.metric_source,
-            c.metric_source_url,
-            c.metric_confidence,
-            c.metric_proof_text
-        ])
-
-    output.seek(0)
-    
-    return StreamingResponse(
-        output,
-        media_type="text/csv",
-        headers={"Content-Disposition": f"attachment; filename=company_export_{datetime.utcnow().strftime('%Y-%m-%d')}.csv"}
-    )
 
 
 def run_wikipedia_reevaluation_task(company_id: int):