Apply audit fixes for pack-sequence (14 findings, 28 new tests)

Cross-validation audit by Codex + Opus identified 14 issues:

CRITICAL:
- Fix _find_subdir_ci() prefix match accepting wrong folders (e.g.
  Publish_old). Now uses exact case-insensitive match.

HIGH:
- Add pack-sequence CLI subcommand with unambiguous arg parsing.
  Deprecate --sequence on pack (nargs='+' consumed the target).
- Fix Windows UNC/drive path normalization in bpathlib.make_absolute()
- Fix ZIP failure losing traceback + progress bar stuck on error
- Fix os.path.commonpath crash on cross-drive paths (new
  derive_common_project helper)
- Fix progress bar saturating at 40% during trace (log scale)

MEDIUM:
- Add per-shot error isolation in sequence scan (collect all errors)
- Add memory warning for >50 files in sequence pack
- Improve pack-info.txt with dedup stats
- Wrap single Path in list for old operators (type consistency)

LOW/INFO:
- Document VERSION_RE pattern
- Add TASK_CHOICE_ITEMS empty guard

28 new tests in tests/test_sequence_pack.py, 0 regressions.

Co-Authored-By: Mario Hawat <mario@autourdeminuit.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

blender_asset_tracer/cli/__init__.py

@@ -79,6 +79,7 @@ def cli_main():
 
     blocks.add_parser(subparsers)
     pack.add_parser(subparsers)
+    pack.add_sequence_parser(subparsers)
     list_deps.add_parser(subparsers)
     version.add_parser(subparsers)
 

blender_asset_tracer/cli/pack.py

@@ -104,12 +104,122 @@ def add_parser(subparsers):
         nargs="+",
         type=pathlib.Path,
         metavar="BLENDFILE",
-        help="Pack multiple blend files together, deduplicating shared dependencies. "
-        "All listed blend files and their dependencies are packed into the target.",
+        help="(Deprecated: use 'pack-sequence' subcommand instead.) "
+        "Pack multiple blend files together, deduplicating shared dependencies.",
     )
 
 
+def add_sequence_parser(subparsers):
+    """Add argparser for the pack-sequence subcommand."""
+
+    parser = subparsers.add_parser(
+        "pack-sequence",
+        help="Pack multiple blend files together, deduplicating shared dependencies.",
+    )
+    parser.set_defaults(func=cli_pack_sequence)
+    parser.add_argument(
+        "blendfiles",
+        nargs="+",
+        type=pathlib.Path,
+        help="Blend files to pack.",
+    )
+    parser.add_argument(
+        "-t",
+        "--target",
+        type=str,
+        required=True,
+        help="Target directory or ZIP file.",
+    )
+    parser.add_argument(
+        "-p",
+        "--project",
+        type=pathlib.Path,
+        help="Root directory of your project.",
+    )
+    parser.add_argument(
+        "-n",
+        "--noop",
+        default=False,
+        action="store_true",
+        help="Don't copy files, just show what would be done.",
+    )
+    parser.add_argument(
+        "-e",
+        "--exclude",
+        nargs="*",
+        default="",
+        help="Space-separated list of glob patterns to exclude.",
+    )
+    parser.add_argument(
+        "-c",
+        "--compress",
+        default=False,
+        action="store_true",
+        help="Compress blend files while copying.",
+    )
+    parser.add_argument(
+        "-r",
+        "--relative-only",
+        default=False,
+        action="store_true",
+        help="Only pack assets referred to with a relative path.",
+    )
+
+
+def derive_common_project(bpaths: typing.List[pathlib.Path]) -> pathlib.Path:
+    """Derive common project directory from multiple blend file paths.
+
+    Raises ValueError if paths span multiple drives or if common root
+    is the filesystem root.
+    """
+    if len(bpaths) == 1:
+        return bpaths[0].parent
+
+    try:
+        ppath = pathlib.Path(os.path.commonpath([p.parent for p in bpaths]))
+    except ValueError:
+        raise ValueError(
+            "Blend files span multiple drives or have no common path. "
+            "Specify the project directory explicitly with -p/--project."
+        )
+
+    if ppath == pathlib.Path(ppath.anchor):
+        raise ValueError(
+            "Computed project path is the filesystem root (%s). "
+            "Specify the project directory explicitly." % ppath
+        )
+
+    return ppath
+
+
+def cli_pack_sequence(args):
+    """CLI entry point for pack-sequence subcommand."""
+    # Synthesize args to reuse paths_from_cli and create_packer
+    args.blendfile = None
+    args.sequence = args.blendfiles
+    args.keep_hierarchy = True  # always for sequence packing
+    if not hasattr(args, 'target') or args.target is None:
+        log.critical("No target specified. Use -t/--target.")
+        sys.exit(3)
+
+    bpaths, ppath, tpath = paths_from_cli(args)
+
+    with create_packer(args, bpaths, ppath, tpath) as packer:
+        packer.strategise()
+        try:
+            packer.execute()
+        except blender_asset_tracer.pack.transfer.FileTransferError as ex:
+            log.error(
+                "%d files couldn't be copied, starting with %s",
+                len(ex.files_remaining),
+                ex.files_remaining[0],
+            )
+            raise SystemExit(1)
+
+
 def cli_pack(args):
+    if args.sequence:
+        log.warning("--sequence on 'pack' is deprecated. Use 'bat pack-sequence -t TARGET FILE...' instead.")
     bpaths, ppath, tpath = paths_from_cli(args)
 
     with create_packer(args, bpaths, ppath, tpath) as packer:
@@ -270,10 +380,11 @@ def paths_from_cli(args) -> typing.Tuple[typing.List[pathlib.Path], pathlib.Path
     tpath = args.target
 
     if args.project is None:
-        if len(bpaths) == 1:
-            ppath = bpaths[0].parent
-        else:
-            ppath = pathlib.Path(os.path.commonpath([p.parent for p in bpaths]))
+        try:
+            ppath = derive_common_project(bpaths)
+        except ValueError as ex:
+            log.critical("%s", ex)
+            sys.exit(5)
         log.warning("No project path given, using %s", ppath)
     else:
         ppath = bpathlib.make_absolute(args.project)