Configure database path to /tmp/users.db on Linux to support write operations in Hugging Face read-only containers

app.py

@@ -129,7 +129,8 @@ DISEASE_INFO = {
 # ──────────────────────────────────────────────
 
 def get_db():
-    conn = sqlite3.connect("users.db")
+    db_path = "/tmp/users.db" if os.name != "nt" else "users.db"
+    conn = sqlite3.connect(db_path)
     conn.row_factory = sqlite3.Row
     return conn