fix(backup,restore): harden the branch fixes and prove them with tests

Backup: a container that vanishes between the docker ps listing and the
swarm-task inspect (--rm one-shots, task-history GC) no longer aborts the
whole backup run; it counts as not stoppable and is skipped.

Restore: the postgres replay streams the dump through a spooled temp file
instead of buffering it three times in memory (multi-GB dumps OOMed the
restore mid-replay), and the superuser-only line filter is COPY-aware: data
rows inside COPY ... FROM stdin blocks pass through untouched, so a row
that happens to start with COMMENT ON EXTENSION or ALTER DEFAULT PRIVILEGES
is no longer silently dropped.

The e2e runner talks to the DinD daemon through docker exec instead of a
host-published tcp://127.0.0.1:2375: port publishing is unreachable from
sandboxed runners and from hosts with broken loopback publishing, and the
unencrypted root API port disappears from the host. The debug tmp dump
shrinks to tar plus docker cp against the DinD container itself.

New coverage: an e2e reproducing the swarm flake end to end (service task
on the volume, nothing whitelisted: the backup must succeed, the very same
task container must keep running, and the service must never replace a
task), unit tests for the COPY-aware filter, the swarm-task probe including
the vanished-container path, filter_stoppable ordering, and the one-session
FOREIGN_KEY_CHECKS drop assembly. Full suite: 35 unit, 9 integration,
30 e2e green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/baudolo/backup/docker.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from .shell import execute_shell_command
+from .shell import BackupException, execute_shell_command
 
 
 def get_image_info(container: str) -> str:
@@ -27,11 +27,16 @@ def containers_using_volume(volume_name: str) -> list[str]:
 def is_swarm_task(container: str) -> bool:
     """Swarm-managed task containers must never be stopped or started
     manually: the orchestrator replaces the stopped task and a later
-    `docker start` fails on the detached overlay network."""
-    out = execute_shell_command(
-        "docker inspect --format "
-        f"'{{{{index .Config.Labels \"com.docker.swarm.task.id\"}}}}' {container}"
-    )
+    `docker start` fails on the detached overlay network. A container that
+    vanished between listing and inspect (--rm one-shots, task-history GC)
+    counts as not stoppable instead of aborting the whole backup run."""
+    try:
+        out = execute_shell_command(
+            "docker inspect --format "
+            f"'{{{{index .Config.Labels \"com.docker.swarm.task.id\"}}}}' {container}"
+        )
+    except BackupException:
+        return True
     return bool(out and out[0].strip())