feat(codex): add mcp_config_remote_path support to match claude-code #886

Context

The coder/claude-code module has a mcp_config_remote_path variable (added in the v5 refactor, #861) that accepts a list of URLs returning JSON MCP server configurations. These are fetched at install time and added to the user's MCP scope.

The coder-labs/codex module (refactored to match claude-code v5 in #879) does not have an equivalent variable.

Request

Add a mcp_config_remote_path variable to the codex module that fetches remote MCP server configs (in TOML format, matching codex's native config format) and appends them to config.toml at install time.

Reference

• Claude-code implementation: registry/coder/modules/claude-code/main.tf (mcp_config_remote_path variable)
• Claude-code install script: registry/coder/modules/claude-code/scripts/install.sh.tftpl (fetch + parse logic)
• Variable alignment PR: fix(registry/coder-labs/modules/codex): align variable names with claude-code v5 #885