Add version command with comprehensive unit tests and build integration

- Implement llama version command with table and JSON output formats
- Add build-time git information capture via scripts/generate_build_info.py
- Include comprehensive unit test suite (test_version.py, test_version_simple.py, test_version_integration.py)
- Add build system integration with custom setup.py command
- Update .gitignore to exclude generated build info file

Features:
- Display Llama Stack and client versions
- Show Python version and build information (git commit, date, branch, tag)
- Optional component/provider listing organized by API
- Support for both table and JSON output formats
- Build-time capture of git metadata for version tracking

Testing:
- 8 unit tests covering all functionality
- Integration tests for CLI execution
- Simple dependency-free validation tests
- Documentation for test suite and build process

Signed-off-by: Akram Ben Aissi <akram.benaissi@gmail.com>

scripts/generate_build_info.py

@@ -0,0 +1,151 @@
+#!/usr/bin/env python3
+
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+# This file is auto-generated during build time
+# DO NOT EDIT MANUALLY
+
+import subprocess
+import sys
+from datetime import UTC, datetime
+from pathlib import Path
+
+
+def get_git_info():
+    """Get git information for build"""
+    git_info = {
+        "git_commit": "unknown",
+        "git_commit_date": "unknown",
+        "git_branch": "unknown",
+        "git_tag": "unknown",
+    }
+
+    try:
+        # Get current directory - assume script is in scripts/ directory
+        repo_root = Path(__file__).parent.parent
+
+        # Get commit hash
+        result = subprocess.run(
+            ["git", "rev-parse", "HEAD"],
+            cwd=repo_root,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+        if result.returncode == 0:
+            git_info["git_commit"] = result.stdout.strip()[:12]  # Short hash
+
+        # Get commit date
+        result = subprocess.run(
+            ["git", "log", "-1", "--format=%ci"],
+            cwd=repo_root,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+        if result.returncode == 0:
+            git_info["git_commit_date"] = result.stdout.strip()
+
+        # Get current branch
+        result = subprocess.run(
+            ["git", "rev-parse", "--abbrev-ref", "HEAD"],
+            cwd=repo_root,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+        if result.returncode == 0:
+            branch = result.stdout.strip()
+            # If we're in detached HEAD state (common in CI), try to get branch from env
+            if branch == "HEAD":
+                # Try common CI environment variables
+                import os
+
+                branch = (
+                    os.getenv("GITHUB_REF_NAME")
+                    or os.getenv("CI_COMMIT_REF_NAME")  # GitLab
+                    or os.getenv("BUILDKITE_BRANCH")
+                    or os.getenv("TRAVIS_BRANCH")
+                    or "HEAD"
+                )
+            git_info["git_branch"] = branch
+
+        # Get latest tag
+        result = subprocess.run(
+            ["git", "describe", "--tags", "--abbrev=0"],
+            cwd=repo_root,
+            capture_output=True,
+            text=True,
+            timeout=10,
+        )
+        if result.returncode == 0:
+            git_info["git_tag"] = result.stdout.strip()
+        else:
+            # If no tags, try to get the closest tag with distance
+            result = subprocess.run(
+                ["git", "describe", "--tags", "--always"],
+                cwd=repo_root,
+                capture_output=True,
+                text=True,
+                timeout=10,
+            )
+            if result.returncode == 0:
+                git_info["git_tag"] = result.stdout.strip()
+
+    except (subprocess.TimeoutExpired, subprocess.SubprocessError, FileNotFoundError) as e:
+        print(f"Warning: Could not get git information: {e}", file=sys.stderr)
+
+    return git_info
+
+
+def generate_build_info_file():
+    """Generate the build_info.py file with current git information"""
+    git_info = get_git_info()
+
+    # Add build timestamp
+    build_timestamp = datetime.now(UTC).isoformat()
+
+    # Get the target file path
+    script_dir = Path(__file__).parent
+    target_file = script_dir.parent / "llama_stack" / "cli" / "build_info.py"
+
+    # Generate the content
+    content = f"""#!/usr/bin/env python3
+
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+# This file is auto-generated during build time
+# DO NOT EDIT MANUALLY
+
+BUILD_INFO = {{
+    "git_commit": "{git_info["git_commit"]}",
+    "git_commit_date": "{git_info["git_commit_date"]}",
+    "git_branch": "{git_info["git_branch"]}",
+    "git_tag": "{git_info["git_tag"]}",
+    "build_timestamp": "{build_timestamp}",
+}}
+"""
+
+    # Write the file
+    try:
+        target_file.write_text(content)
+        print(f"Generated build info file: {target_file}")
+        print(f"Git commit: {git_info['git_commit']}")
+        print(f"Git branch: {git_info['git_branch']}")
+        print(f"Git tag: {git_info['git_tag']}")
+        print(f"Build timestamp: {build_timestamp}")
+    except Exception as e:
+        print(f"Error writing build info file: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    generate_build_info_file()