fix: adjust confidence calculation and streamline model download logic

app/routes/analyze.py

@@ -516,7 +516,7 @@ async def _analyze_file(
     final_decision = fusion.decision_source
     if xai_payload is not None:
         final_is_ai = xai_payload.probability >= xai_payload.threshold
-        final_confidence = round(xai_payload.probability, 4)
+        final_confidence = round(max(0.03, min(0.97, xai_payload.probability)), 4)
         final_decision = f"auris_xai_{xai_payload.bestModel.lower()}"
 
     result = AnalysisResult(

startup.py

@@ -104,12 +104,10 @@ def download_models() -> None:
             print(f"[startup]   skip  {filename} (exists)")
             continue
 
-        if filename not in repo_files and filename not in REQUIRED_FILES:
-            if filename in OPTIONAL_FILES:
-                print(f"[startup]   skip  {filename} (not in repo, optional)")
-                continue
-
         is_optional = filename in OPTIONAL_FILES
+        if filename not in repo_files and is_optional:
+            print(f"[startup]   skip  {filename} (not in repo, optional)")
+            continue
         try:
             print(f"[startup]   dl    {filename} ...", end=" ", flush=True)
             path = hf_hub_download(