feat: слои db.py + test_routes (Blueprint /test)

site/db.py

@@ -0,0 +1,36 @@
+import os
+import psycopg2
+from psycopg2 import sql
+
+
+def connect():
+    """Подключение к БД. Возвращает connection или None."""
+    try:
+        return psycopg2.connect(
+            host=os.getenv("DB_HOST"),
+            port=os.getenv("DB_PORT", 5432),
+            dbname=os.getenv("DB_NAME"),
+            user=os.getenv("DB_USER"),
+            password=os.getenv("DB_PASS"),
+            sslmode=os.getenv("DB_SSLMODE", "disable"),
+        )
+    except Exception:
+        return None
+
+
+def query(sql_text, params=None):
+    """Выполнить запрос, вернуть (rows, columns) или (None, error)."""
+    conn = connect()
+    if not conn:
+        return None, "no connection"
+    try:
+        cur = conn.cursor()
+        cur.execute(sql_text, params)
+        rows = cur.fetchall()
+        cols = [desc[0] for desc in cur.description] if cur.description else []
+        cur.close()
+        conn.close()
+        return {"columns": cols, "rows": [list(r) for r in rows]}, None
+    except Exception as e:
+        conn.close()
+        return None, str(e)