fix: security and reliability improvements

- Switch HTTPServer to ThreadingHTTPServer (concurrent request handling)
- Replace SHA-256 password hashing with bcrypt (auth.py, database.py)
- Add bcrypt to Dockerfile
- Move qBittorrent env vars to config.py
- Move _booklore_token state out of config into booklore.py
- Remove dead fitness_token variable in command.py
- Fix OpenAI call to use default SSL context instead of no-verify ctx
- Log swallowed budget fetch error in dashboard.py

gateway/dashboard.py

@@ -222,7 +222,7 @@ def handle_dashboard(handler, user):
                 data = json.loads(b)
                 return {"count": data.get("transactionCount", 0), "totalBalance": data.get("totalBalanceDollars", 0), "spending": data.get("spendingDollars", 0), "income": data.get("incomeDollars", 0), "topCategories": data.get("topCategories", [])[:5], "month": data.get("month", "")}
         except Exception as e:
-            pass
+            print(f"[Dashboard] Budget fetch error: {e}")
         return None
 
     def fetch_reader(app):