## Summary

- Add per-host rsync bandwidth limit overrides with inherit/unlimited semantics.
- Store the effective bwlimit in run metadata/results and show it in host/run detail views.
- Document recommended starting values for VPN and remote backups.

## Tests
- `.venv/bin/python manage.py makemigrations --check --dry-run`
- `.venv/bin/python manage.py test src.pobsync_backend.tests.test_django_config_source.DjangoConfigSourceTests.test_returns_effective_config_from_database src.pobsync_backend.tests.test_django_config_source.DjangoConfigSourceTests.test_host_can_disable_global_rsync_bandwidth_limit src.pobsync_backend.tests.test_configure_commands.ConfigureCommandsTests.test_configure_host_uses_global_retention_defaults src.pobsync_backend.tests.test_run_scheduled_config_source.RunScheduledConfigSourceTests.test_dry_run_applies_configured_bandwidth_limit src.pobsync_backend.tests.test_run_scheduled_config_source.RunScheduledConfigSourceTests.test_real_run_can_request_verbose_output_args --verbosity 2`
- `.venv/bin/python manage.py test src.pobsync_backend.tests.test_views.ViewTests.test_create_host_config_form_creates_host src.pobsync_backend.tests.test_views.ViewTests.test_host_detail_renders_effective_config_preview src.pobsync_backend.tests.test_views.ViewTests.test_run_detail_renders_result_payload src.pobsync_backend.tests.test_views.ViewTests.test_host_config_form_updates_host_config --verbosity 2`
- `.venv/bin/python manage.py check`

Closes #51

src/pobsync_backend/tests/test_django_config_source.py

@@ -17,6 +17,7 @@ class DjangoConfigSourceTests(TestCase):
             backup_root="/backups",
             rsync_args=["--archive"],
             rsync_extra_args=["--numeric-ids"],
+            rsync_bwlimit_kbps=10000,
             excludes_default=["/proc/***"],
             retention_daily=7,
             retention_weekly=4,
@@ -28,6 +29,7 @@ class DjangoConfigSourceTests(TestCase):
             address="web-01.example.test",
             excludes_add=["/tmp/***"],
             rsync_extra_args=["--delete"],
+            rsync_bwlimit_kbps=2500,
             retention_daily=7,
             retention_weekly=4,
             retention_monthly=3,
@@ -46,6 +48,24 @@ class DjangoConfigSourceTests(TestCase):
         self.assertEqual(cfg["address"], "web-01.example.test")
         self.assertEqual(cfg["excludes_effective"], ["/proc/***", "/tmp/***"])
         self.assertEqual(cfg["rsync"]["args_effective"], ["--archive", "--numeric-ids", "--delete"])
+        self.assertEqual(cfg["rsync"]["bwlimit_kbps"], 2500)
+
+    def test_host_can_disable_global_rsync_bandwidth_limit(self) -> None:
+        GlobalConfig.objects.create(
+            name="default",
+            backup_root="/backups",
+            rsync_args=["--archive"],
+            rsync_bwlimit_kbps=5000,
+        )
+        HostConfig.objects.create(
+            host="web-01",
+            address="web-01.example.test",
+            rsync_bwlimit_kbps=0,
+        )
+
+        cfg = DjangoConfigSource().effective_config_for_host("web-01")
+
+        self.assertEqual(cfg["rsync"]["bwlimit_kbps"], 0)
 
     def test_materializes_global_ssh_credential_for_runtime_config(self) -> None:
         credential = SshCredential.objects.create(