Carry investigation decision criteria and offer grounded query narrowing

src/viano_bug_analysis/llm/gemini.py

@@ -134,7 +134,7 @@ class GeminiProvider:
         if config.use_context_cache:
             status = 'below_minimum'
             if (len(json_bytes([system, prefix]).decode('utf-8')) >= config.cache_min_prefix_chars
-                    or request['prompt_version'] in {'investigation_project_v15','investigation_project_v16','investigation_project_v17'}):
+                    or request['prompt_version'] in {'investigation_project_v15','investigation_project_v16','investigation_project_v17','investigation_project_v18'}):
                 with self._lock:
                     now = time.monotonic()
                     self._cache = {k: v for k, v in self._cache.items() if v[1] > now}