feat(backup)!: exact --images-* matching and --hard-restart-projects

Match --images-no-stop-required and --images-no-backup-required against
the container's exact .Config.Image instead of a substring, so callers
pass full repo:tag references (registry prefix included) and near-miss
image names no longer flip the stop/skip decision. Rename the opt-in
--hard-compose-restart flag to --hard-restart-projects.

The e2e suite pins a SPOT for the DB images and in-container data dirs
(postgres:alpine at /var/lib/postgresql, mariadb:latest at
/var/lib/mysql) and passes exact image refs to the --images-* flags.

BREAKING CHANGE: --images-* now require exact image references, not
substrings; --hard-compose-restart is renamed to --hard-restart-projects.

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

src/baudolo/backup/cli.py

@@ -17,7 +17,7 @@ def parse_args() -> argparse.Namespace:
         help="Path to the parent directory containing docker-compose setups",
     )
     p.add_argument(
-        "--hard-compose-restart",
+        "--hard-restart-projects",
         nargs="*",
         default=[],
         help="Compose dir names that require 'docker-compose down && up -d' (default: none; pass e.g. 'mailu' under compose where the DB cannot be backed up hot)",
@@ -49,13 +49,13 @@ def parse_args() -> argparse.Namespace:
         "--images-no-stop-required",
         nargs="+",
         required=True,
-        help="Image name patterns for which containers should not be stopped during file backup",
+        help="Exact image references (repo:tag, incl. any registry prefix) whose containers must not be stopped during file backup",
     )
     p.add_argument(
         "--images-no-backup-required",
         nargs="+",
         default=[],
-        help="Image name patterns for which no backup should be performed",
+        help="Exact image references (repo:tag, incl. any registry prefix) for which no backup should be performed",
     )
 
     p.add_argument(