Render statusline before MCP/plugin initialization completes

Summary

The statusline (configured via settings.json → statusLine.command) doesn't render until the entire session initialization is complete — including all MCP server connections and plugin loading. On setups with many MCP servers/plugins, this means the statusline is invisible for 20-30 seconds after Claude Code starts.

Problem

The statusline command itself executes in <1s, but it isn't invoked until after all MCP servers connect and plugins load. With ~24 MCP servers and 60+ plugins, session initialization takes 20-30s. During this time the user sees no statusline — no model info, no context usage, no cost tracking.

Proposed Change

Invoke the statusline command early in the startup sequence (e.g., right after parsing settings and before MCP/plugin initialization begins). The statusline input JSON could contain partial/default values for fields not yet available. This gives users immediate visual feedback while MCP servers connect in the background.

Environment

• Windows 11, CLI
• 24 MCP servers, 60+ enabled plugins
• statusLine.type: "command"