Add a simple --version flag (#5516)

* Add a simple --version flag

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Small code clean-up, less ugly

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Slightly better function names. And use again None

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Roland Tannous <115670425+rolandtannous@users.noreply.github.com>

unsloth_cli/__init__.py

@@ -2,17 +2,45 @@
 # Copyright 2026-present the Unsloth AI Inc. team. All rights reserved. See /studio/LICENSE.AGPL-3.0
 
 import typer
+from importlib.metadata import version as package_version, PackageNotFoundError
+
 
 from unsloth_cli.commands.train import train
 from unsloth_cli.commands.inference import inference
 from unsloth_cli.commands.export import export, list_checkpoints
 from unsloth_cli.commands.studio import run as studio_run, studio_app
 
+
+def show_version(value: bool):
+    if value:
+        try:
+            version = package_version("unsloth")
+        except PackageNotFoundError:
+            version = "unknown"
+        typer.echo(f"unsloth {version}")
+        raise typer.Exit()
+
+
 app = typer.Typer(
     help = "Command-line interface for Unsloth training, inference, and export.",
     context_settings = {"help_option_names": ["-h", "--help"]},
 )
 
+
+@app.callback()
+def main(
+    version: bool = typer.Option(
+        None,
+        "--version",
+        "-V",
+        callback = show_version,
+        is_eager = True,
+        help = "Show version and exit.",
+    ),
+):
+    pass
+
+
 app.command()(train)
 app.command()(inference)
 app.command()(export)