feat(backup)!: mandatory repo-name and databases-csv, --only-files, --only-sql

Two defaults could not be right. --repo-name fell back to the literal 'backup-docker-to-local' while its help promised the git repo folder name, which nothing ever derived. --databases-csv pointed inside the installed package directory, where credentials must not live; when it applied, load_databases_df read a missing file as empty and the run finished without a single dump and without an error. Both are required now, --repo-name in the restore CLI too. The file itself may still be absent - babadcb's tolerance is untouched, only the path must be named.

--everything is withdrawn. Its one effect was to ignore --images-no-stop-required, which is what leaving that list empty already does, and its branch was the default path minus the requires_stop check. No caller, no test, and help and README described it differently.

--dump-only-sql becomes --only-sql, and --only-files joins it as the opposite half: no dumps at all, every volume as files. They form a mutually exclusive group. A host that only copies files has no business holding database passwords, so --databases-csv is not required there and is never read.

The smallest valid argv turned out to be written four times across the test tree; it now lives once. Withdrawn flags are listed in one place and proven to exit 2.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/baudolo/backup/app.py

@@ -37,7 +37,7 @@ def main() -> int:
     versions_dir = os.path.join(args.backups_dir, machine_id, args.repo_name)
     version_dir = create_version_directory(versions_dir, backup_time)
 
-    databases_df = load_databases_df(args.databases_csv)
+    databases_df = None if args.only_files else load_databases_df(args.databases_csv)
 
     print("💾 Start volume backups...", flush=True)
 
@@ -69,17 +69,19 @@ def main() -> int:
 
             vol_dir = create_volume_directory(version_dir, volume_name)
 
-            found_db, dumped_any = backup_dumps_for_volume(
-                containers=containers,
-                vol_dir=vol_dir,
-                databases_df=databases_df,
-                database_containers=args.database_containers,
-            )
+            found_db = dumped_any = False
+            if not args.only_files:
+                found_db, dumped_any = backup_dumps_for_volume(
+                    containers=containers,
+                    vol_dir=vol_dir,
+                    databases_df=databases_df,
+                    database_containers=args.database_containers,
+                )
 
-            if args.dump_only_sql and found_db:
+            if args.only_sql and found_db:
                 if not dumped_any:
                     print(
-                        f"WARNING: dump-only-sql requested but no DB dump was produced for DB volume '{volume_name}'. "
+                        f"WARNING: only-sql requested but no DB dump was produced for DB volume '{volume_name}'. "
                         "Falling back to file backup.",
                         flush=True,
                     )
@@ -119,15 +121,6 @@ def main() -> int:
                     copy(authoritative=False)
                 continue
 
-            if args.everything:
-                stoppable = filter_stoppable(containers)
-                copy(authoritative=False)
-                change_containers_status(stoppable, "stop")
-                copy(authoritative=True)
-                if not args.shutdown:
-                    change_containers_status(stoppable, "start")
-                continue
-
             copy(authoritative=False)
             if requires_stop(containers, args.images_no_stop_required):
                 stoppable = filter_stoppable(containers)