(bugfix) Guard dry-run logs and recursive rsync defaults

Clear the reused dry-run rsync log before each dry-run so run details
only show output from the current execution.

Populate new Django global configs with the existing safe rsync and
exclude defaults, including archive mode and standard pseudo-filesystem
exclusions.

Add a host check that fails when effective rsync args do not include
archive or recursive transfer, preventing real backups that only report
"skipping directory .".

src/pobsync_backend/host_ops.py

@@ -78,9 +78,31 @@ def collect_host_checks(host: HostConfig, global_config: GlobalConfig | None = N
     checks.append(_host_path_check("Host backup root", host_root, must_exist=True, must_be_writable=True))
     for subdir in HOST_BACKUP_SUBDIRS:
         checks.append(_host_path_check(f"Host directory: {subdir}", host_root / subdir, must_exist=True, must_be_writable=True))
+    checks.append(_rsync_recursion_check(host, global_config))
     return checks
 
 
+def _rsync_recursion_check(host: HostConfig, global_config: GlobalConfig) -> SelfCheck:
+    args = [*list(global_config.rsync_args or []), *list(global_config.rsync_extra_args or []), *list(host.rsync_extra_args or [])]
+    if _has_recursive_rsync_arg(args):
+        return SelfCheck("Host rsync recursion", "ok", "Rsync args include archive or recursive transfer.", " ".join(args))
+    return SelfCheck(
+        "Host rsync recursion",
+        "failed",
+        "Rsync args do not include archive or recursive transfer.",
+        "Add --archive or --recursive before running a real backup.",
+    )
+
+
+def _has_recursive_rsync_arg(args: list[str]) -> bool:
+    for arg in args:
+        if arg in {"--archive", "--recursive"}:
+            return True
+        if arg.startswith("-") and not arg.startswith("--") and any(flag in arg for flag in ("a", "r")):
+            return True
+    return False
+
+
 def _host_path_check(
     name: str,
     path: Path,

src/pobsync_backend/tests/test_run_scheduled_config_source.py

@@ -67,6 +67,28 @@ class RunScheduledConfigSourceTests(SimpleTestCase):
         self.assertEqual(result["rsync"]["exit_code"], 12)
         self.assertEqual(result["rsync"]["log_tail"], ["Permission denied (publickey).", "rsync error"])
 
+    def test_dry_run_clears_previous_log_before_running(self) -> None:
+        def fake_run_rsync(command, log_path, timeout_seconds):
+            self.assertFalse(log_path.exists())
+            log_path.parent.mkdir(parents=True, exist_ok=True)
+            log_path.write_text("current run only\n", encoding="utf-8")
+            return RsyncResult(exit_code=0, command=command)
+
+        old_log = Path("/tmp/pobsync-dryrun/web-01/rsync.log")
+        old_log.parent.mkdir(parents=True, exist_ok=True)
+        old_log.write_text("old failure\n", encoding="utf-8")
+
+        with patch("pobsync.commands.run_scheduled.run_rsync", side_effect=fake_run_rsync):
+            result = run_scheduled(
+                prefix=Path("/missing-prefix"),
+                host="web-01",
+                dry_run=True,
+                config_source=FakeConfigSource(),
+            )
+
+        self.assertTrue(result["ok"])
+        self.assertEqual(result["rsync"]["log_tail"], ["current run only"])
+
     def test_successful_real_run_applies_prune_when_requested(self) -> None:
         with TemporaryDirectory() as tmp:
             prefix = Path(tmp) / "home"

src/pobsync_backend/tests/test_views.py

@@ -331,6 +331,8 @@ class ViewTests(TestCase):
 
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, f'value="{credential.id}" selected')
+        self.assertContains(response, "--archive")
+        self.assertContains(response, "/proc/***")
 
     def test_global_config_form_renders_static_container_backup_root_on_edit(self) -> None:
         self.client.force_login(self.staff_user)
@@ -522,6 +524,17 @@ class ViewTests(TestCase):
             self.assertTrue((backup_root / host.host / "manual").is_dir())
             self.assertTrue((backup_root / host.host / ".incomplete").is_dir())
 
+    def test_host_detail_warns_when_rsync_is_not_recursive(self) -> None:
+        self.client.force_login(self.staff_user)
+        GlobalConfig.objects.create(name="default", backup_root="/backups", rsync_args=[])
+        host = HostConfig.objects.create(host="web-01", address="web-01.example.test")
+
+        response = self.client.get(reverse("host_detail", args=[host.host]))
+
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, "Host rsync recursion")
+        self.assertContains(response, "Rsync args do not include archive or recursive transfer.")
+
     def test_scan_host_known_key_action_updates_selected_credential(self) -> None:
         self.client.force_login(self.staff_user)
         credential = SshCredential.objects.create(name="default-key", key_path="/var/lib/pobsync/state/ssh-credentials/1/identity")

src/pobsync_backend/views.py

@@ -13,6 +13,7 @@ from django.shortcuts import get_object_or_404, redirect, render
 from django.views.decorators.http import require_POST
 
 from pobsync.errors import PobsyncError
+from pobsync.config.defaults import DEFAULT_EXCLUDES, DEFAULT_RSYNC_ARGS
 
 from .backup_runner import queue_backup_run
 from .forms import (
@@ -519,7 +520,9 @@ def _default_global_initial() -> dict[str, object]:
         "ssh_user": "root",
         "ssh_port": 22,
         "rsync_binary": "rsync",
+        "rsync_args": DEFAULT_RSYNC_ARGS,
         "default_source_root": "/",
+        "excludes_default": DEFAULT_EXCLUDES,
         "retention_daily": 14,
         "retention_weekly": 8,
         "retention_monthly": 12,