rework server startup and cli

This changes the dockerfile as well.

src/embeddingbuddy/cli.py

@@ -0,0 +1,74 @@
+"""
+Lightweight CLI entry point for EmbeddingBuddy.
+
+This module provides a fast command-line interface that only imports
+heavy dependencies when actually needed by subcommands.
+"""
+import argparse
+import sys
+
+
+def main():
+    """Main CLI entry point with minimal imports for fast help text."""
+    parser = argparse.ArgumentParser(
+        prog="embeddingbuddy",
+        description="EmbeddingBuddy - Interactive embedding visualization tool",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  embeddingbuddy serve                    # Production mode (no debug, no auto-reload)
+  embeddingbuddy serve --dev              # Development mode (debug + auto-reload)
+  embeddingbuddy serve --debug            # Debug logging only (no auto-reload)
+  embeddingbuddy serve --port 8080        # Custom port
+  embeddingbuddy serve --host 0.0.0.0     # Bind to all interfaces
+        """
+    )
+
+    subparsers = parser.add_subparsers(
+        dest="command",
+        help="Available commands",
+        metavar="<command>"
+    )
+
+    # Serve subcommand
+    serve_parser = subparsers.add_parser(
+        "serve",
+        help="Start the web server",
+        description="Start the EmbeddingBuddy web server for interactive visualization"
+    )
+    serve_parser.add_argument(
+        "--host",
+        default=None,
+        help="Host to bind to (default: 127.0.0.1)"
+    )
+    serve_parser.add_argument(
+        "--port",
+        type=int,
+        default=None,
+        help="Port to bind to (default: 8050)"
+    )
+    serve_parser.add_argument(
+        "--dev",
+        action="store_true",
+        help="Development mode: enable debug logging and auto-reload"
+    )
+    serve_parser.add_argument(
+        "--debug",
+        action="store_true",
+        help="Enable debug logging (no auto-reload)"
+    )
+
+    args = parser.parse_args()
+
+    if args.command == "serve":
+        # Only import heavy dependencies when actually running serve
+        from embeddingbuddy.app import serve
+        serve(host=args.host, port=args.port, dev=args.dev, debug=args.debug)
+    else:
+        # No command specified, show help
+        parser.print_help()
+        sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()