fix(zopk): Use GeminiService instead of raw genai for AI roadmap analysis

The analyze_roadmap_with_ai() was using google.generativeai directly
which bypasses API key configuration. Switch to GeminiService which
has the key pre-configured via init_gemini_service().

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

zopk_knowledge_service.py

@@ -2726,7 +2726,7 @@ def analyze_roadmap_with_ai(db_session) -> Dict:
             'gaps': [...]
         }
     """
-    import google.generativeai as genai
+    from gemini_service import GeminiService
     import json
     from database import ZOPKMilestone
 
@@ -2795,10 +2795,17 @@ Zasady:
 - Jeśli nie ma sugestii w danej kategorii, zwróć pustą listę
 - Tytuły pisz po polsku"""
 
-        model = genai.GenerativeModel("gemini-3-flash-preview")
-        response = model.generate_content(prompt)
+        gemini = GeminiService()
+        response_text = gemini.generate_text(
+            prompt=prompt,
+            temperature=0.2,
+            feature='zopk_roadmap_analysis'
+        )
 
-        response_text = response.text.strip()
+        if not response_text:
+            return {'success': False, 'error': 'Brak odpowiedzi od AI'}
+
+        response_text = response_text.strip()
         # Strip markdown code blocks if present
         if response_text.startswith('```'):
             response_text = response_text.split('```')[1]