add password authentication for bot users

assistant_bot/storage.py

@@ -55,6 +55,11 @@ class AssistantStorage:
                     updated_at TEXT NOT NULL
                 );
 
+                CREATE TABLE IF NOT EXISTS authorized_users (
+                    user_id INTEGER PRIMARY KEY,
+                    authorized_at TEXT NOT NULL
+                );
+
                 CREATE TABLE IF NOT EXISTS memories (
                     id INTEGER PRIMARY KEY AUTOINCREMENT,
                     user_id INTEGER NOT NULL,
@@ -127,6 +132,25 @@ class AssistantStorage:
                     "ALTER TABLE user_settings ADD COLUMN yandex_model TEXT"
                 )
 
+    def is_user_authorized(self, user_id: int) -> bool:
+        with self._connection() as connection:
+            row = connection.execute(
+                "SELECT 1 FROM authorized_users WHERE user_id = ?",
+                (user_id,),
+            ).fetchone()
+        return row is not None
+
+    def authorize_user(self, user_id: int) -> None:
+        with self._connection() as connection:
+            connection.execute(
+                """
+                INSERT INTO authorized_users(user_id, authorized_at)
+                VALUES (?, ?)
+                ON CONFLICT(user_id) DO NOTHING
+                """,
+                (user_id, to_utc_iso(utc_now())),
+            )
+
     def add_conversation_exchange(
         self,
         user_id: int,