Unify dataset/tooling scripts into a single dwarf Typer CLI

Replace the five separately-hyphenated uv entry points (steps-to-parquet,
steps-to-parquet-parallel, migrate-geant-steps, bump-dataset-version,
create-root-files) plus the unregistered hparam_scan.py with one `dwarf`
command exposing convert/migrate/bump-gen/bump-schema/status/
update-manifest/create-manifest/make-root/hparam-scan as subcommands.

Each scripts/*.py module now only holds argparse-free business logic;
scripts/dwarf.py wires it up with Typer, matching giant/cli.py's style.
`dwarf convert` merges the old serial/parallel conversion scripts behind
a --jobs flag (default 1: sequential with plain -o; >1: dataset-layout
fan-out via subprocess).

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

scripts/steps_to_parquet.py

@@ -1,14 +1,8 @@
-#!/usr/bin/env python3
 """Convert the Steps tree from a ROOT file to Parquet.
 
-Usage:
-    uv run python steps_to_parquet.py input.root
-    uv run python steps_to_parquet.py input.root -o output.parquet
-    uv run python steps_to_parquet.py input.root --batch-size "200 MB" --tree Hits
-    uv run python steps_to_parquet.py input1.root input2.root input3.root
+See `uv run dwarf convert --help` for the CLI.
 """
 
-import argparse
 from pathlib import Path
 from typing import Literal
 
@@ -125,50 +119,3 @@ def convert_steps_to_parquet(
     df.write_parquet(output_path, compression=compression)
     print(f"done  ({output_path.stat().st_size / 1e6:.1f} MB)")
     return output_path
-
-
-def main() -> None:
-    parser = argparse.ArgumentParser(
-        description="Convert a Steps (or any flat+jagged) tree in a ROOT file to Parquet."
-    )
-    parser.add_argument("root_files", nargs="+", help="Input ROOT file(s)")
-    parser.add_argument(
-        "-o",
-        "--output",
-        help="Output Parquet file (default: <input>.parquet). "
-        "Only valid with a single input file.",
-    )
-    parser.add_argument(
-        "--batch-size",
-        default="100 MB",
-        help="Uproot read batch size (default: '100 MB').  E.g. '50 MB', '500000' (rows).",
-    )
-    parser.add_argument(
-        "--tree",
-        default="Steps",
-        help="Tree name inside the ROOT file (default: Steps)",
-    )
-    parser.add_argument(
-        "--compression",
-        default="snappy",
-        choices=["snappy", "lz4", "zstd", "gzip", "none"],
-        help="Parquet compression codec (default: snappy)",
-    )
-    args = parser.parse_args()
-
-    if args.output is not None and len(args.root_files) > 1:
-        parser.error("--output can only be used with a single input file")
-
-    compression = "uncompressed" if args.compression == "none" else args.compression
-    for root_file in args.root_files:
-        convert_steps_to_parquet(
-            root_file,
-            output_path=args.output,
-            batch_size=args.batch_size,
-            tree_name=args.tree,
-            compression=compression,
-        )
-
-
-if __name__ == "__main__":
-    main()