codegen(go_schemas): emit standardized single-line copyright header

Match vgi-go's standardized header (drop the © and SPDX Apache-2.0 lines) so
regenerating protocol_schemas.go stays in sync with the repo convention.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: rustyconover

vgi/codegen/go_schemas.py

@@ -170,8 +170,7 @@ def emit(out: TextIO) -> None:
     schemas = collect_schemas()
 
     body = io.StringIO()
-    body.write("// © Copyright 2025-2026, Query.Farm LLC - https://query.farm\n")
-    body.write("// SPDX-License-Identifier: Apache-2.0\n")
+    body.write("// Copyright 2025, 2026 Query Farm LLC - https://query.farm\n")
     body.write("\n")
     body.write("package generated\n")
     body.write("\n")