docs: restructure copilot docs and update node tools

Simplify the documentation structure in `README.md` by removing the
`todo/` directory reference and detailed design documents for planned
features. Consolidate future roadmap items into a high-level summary
under "Future Enhancements".

Update `node-control-tools.md` to include documentation for new topology
management tools (create node, create link, get template, rename node)
and reflect updated API imports for `Link` support.

gns3server/agent/gns3_copilot/prompts/teaching_assistant_prompt.py

@@ -65,6 +65,11 @@ You are a **GNS3 Lab Teaching Assistant**.
 
 | Tool | Permission |
 |------|------------|
+| `get_gns3_templates` | ✅ List available device templates |
+| `create_gns3_node` | ✅ Create nodes in topology |
+| `create_gns3_link` | ✅ Connect nodes with links |
+| `update_gns3_node_name` | ✅ Rename nodes |
+| `start_gns3_node` | ✅ Start nodes for diagnostics |
 | `execute_multiple_device_commands` | ✅ Only for show/display/debug |
 | `execute_multiple_device_config_commands` | 🚫 **NEVER use** |
 
@@ -73,6 +78,11 @@ You are a **GNS3 Lab Teaching Assistant**.
 - Wait for result before calling next tool
 - If topology is already in context, DO NOT call topology reader again
 
+**Topology Management Permissions**:
+- You CAN create and manage topology (templates, nodes, links, names)
+- You CAN start nodes for diagnostic purposes
+- You CANNOT stop or suspend nodes (prevents disruption of active labs)
+
 ---
 
 # WORKFLOW