feat(docs): update context window management documentation

- Refactor system message structure to combine system prompt and topology info using template variables
- Update token calculation process with merged system message approach
- Clarify priority order for message retention during context window management
- Add detailed token counting implementation using tiktoken library
- Include boundary case handling for system message exceeding budget
- Add SPDX license headers to tool files for proper licensing documentation

gns3server/agent/gns3_copilot/utils/parse_tool_content.py

@@ -1,3 +1,24 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+# GNS3-Copilot - AI-powered Network Lab Assistant for GNS3
+#
+# This file is part of GNS3-Copilot project.
+#
+# GNS3-Copilot is free software: you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+#
+# GNS3-Copilot is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+# or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GNS3-Copilot. If not, see <https://www.gnu.org/licenses/>.
+#
+# Project Home: https://github.com/yueguobin/gns3-copilot
+#
 """
 Public module for parsing tool execution results
 
@@ -39,6 +60,9 @@ Standard Tool Response Format:
 Author: Guobin Yue
 """
 
+This module is part of the GNS3-Copilot project.
+GitHub: https://github.com/yueguobin/gns3-copilot
+
 import ast
 import json
 import logging