feat: add name_manually_edited field to User model and update related functionality

- Introduced a new boolean column `name_manually_edited` in the `users` table to control whether user names are overwritten during synchronization with Telegram.
- Updated the `get_or_create_user` function to respect the `name_manually_edited` flag, ensuring names are only updated when the flag is false.
- Implemented a new function `update_user_display_name` to allow manual updates of user names while setting the `name_manually_edited` flag to true.
- Enhanced unit tests to cover the new functionality and ensure correct behavior of name handling based on the `name_manually_edited` flag.

alembic/versions/006_name_manually_edited.py

@@ -0,0 +1,35 @@
+"""Add name_manually_edited to users
+
+Revision ID: 006
+Revises: 005
+Create Date: 2025-02-19
+
+When True, full_name/first_name/last_name are not overwritten by get_or_create_user
+(Telegram sync). Set manually or via update_user_display_name when editing name in DB/API.
+"""
+
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+revision: str = "006"
+down_revision: Union[str, None] = "005"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "users",
+        sa.Column(
+            "name_manually_edited",
+            sa.Boolean(),
+            nullable=False,
+            server_default=sa.text("0"),
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("users", "name_manually_edited")