Fix Serena MCP context: use 'codex' instead of 'copilot'

The --context parameter for Serena MCP should be 'codex', not 'copilot'.
This matches the configuration used in compiled workflows.

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

Author: Copilot

.vscode/mcp.json

@@ -16,7 +16,7 @@
         "serena",
         "start-mcp-server",
         "--context",
-        "copilot",
+        "codex",
         "--project",
         "${workspaceFolder}"
       ],