MCP manifest errors

These errors apply to the compatibility .mcp.json file. For portable packages, ingestion derives this file and .codex-plugin/plugin.json from root plugin.json and mcp.json. The component-path errors above can also refer to these generated files. Fix the source portable configuration; don't rename mcp.json to .mcp.json just because a compatibility diagnostic names it.

Name	Requirement
mcp_manifest_unreadable	.mcp.json must be readable UTF-8 text.
mcp_manifest_json_malformed	.mcp.json must contain valid JSON; malformed syntax is reported with a line number.
mcp_manifest_wrong_type	.mcp.json must contain a JSON object at the top level.
mcp_servers_missing	.mcp.json must contain the top-level mcpServers field.
mcp_servers_wrong_type	mcpServers must be an object.
mcp_server_name_empty	Every MCP server name must contain at least one non-whitespace character.