(release) Prepare 1.2.0

Bump the package version to 1.2.0 and document the operations-focused release
with updater, readonly access, notifications, bandwidth controls, live progress,
and more robust retention cleanup.

Make the CLI version test assert against the package version so future release
bumps do not require changing a hardcoded expected value.

src/pobsync/__init__.py

@@ -1,2 +1,2 @@
 __all__ = ["__version__"]
-__version__ = "1.1.0"
+__version__ = "1.2.0"

src/pobsync_backend/tests/test_console_entrypoint.py

@@ -5,6 +5,7 @@ from unittest.mock import patch
 
 from django.test import SimpleTestCase
 
+from pobsync import __version__
 from pobsync.cli import main
 
 
@@ -15,7 +16,7 @@ class ConsoleEntrypointTests(SimpleTestCase):
             exit_code = main(["--version"])
 
         self.assertEqual(exit_code, 0)
-        self.assertEqual(stdout.getvalue().strip(), "pobsync 1.1.0")
+        self.assertEqual(stdout.getvalue().strip(), f"pobsync {__version__}")
 
     def test_maps_backup_alias_to_django_command(self) -> None:
         with patch("pobsync.cli.execute_from_command_line") as execute: