fix: handle datetime/Decimal objects in SEO audit JSONB serialization

SEOAuditor result dict contains datetime objects that can't be serialized
to JSONB. Added _make_json_safe() to recursively convert them.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

blueprints/admin/routes_portal_seo.py

@@ -8,7 +8,8 @@ Tracks results over time for before/after comparison.
 
 import logging
 import json
-from datetime import datetime
+from datetime import datetime, date
+from decimal import Decimal
 
 from flask import abort, render_template, request, redirect, url_for, flash, jsonify
 from flask_login import login_required, current_user
@@ -22,6 +23,19 @@ logger = logging.getLogger(__name__)
 PORTAL_URL = 'https://nordabiznes.pl'
 
 
+def _make_json_safe(obj):
+    """Recursively convert datetime/Decimal objects to JSON-serializable types."""
+    if isinstance(obj, dict):
+        return {k: _make_json_safe(v) for k, v in obj.items()}
+    elif isinstance(obj, list):
+        return [_make_json_safe(v) for v in obj]
+    elif isinstance(obj, (datetime, date)):
+        return obj.isoformat()
+    elif isinstance(obj, Decimal):
+        return float(obj)
+    return obj
+
+
 @bp.route('/portal-seo')
 @login_required
 def admin_portal_seo():
@@ -109,8 +123,8 @@ def admin_portal_seo_run():
             page_size_bytes=on_page.get('page_size_bytes'),
             image_count=on_page.get('total_images'),
             images_without_alt=on_page.get('images_without_alt'),
-            # Full data
-            full_results=result,
+            # Full data (sanitize for JSONB - datetime/Decimal not serializable)
+            full_results=_make_json_safe(result),
             notes=request.form.get('notes', ''),
             created_by=current_user.email
         )