`rayfin --help` is unexpectedly slow compared to subcommand help

Context

Split from https://github.com/microsoft/rayfin/issues/24 (sub-issue 2 of 4).

Problem

Running rayfin --help takes a noticeably long time to render output, while rayfin docs --help renders quickly. The slowness appears specific to the top-level --help path and hurts the first impression of the CLI.

Expected Behavior

rayfin --help should render as fast as subcommand help (e.g., rayfin docs --help).

Investigation Notes

Likely causes:

• Top-level help may be eagerly loading all subcommand modules before rendering
• Possible network calls (e.g., update checks) blocking the help output
• Heavy module initialization that isn't needed for help display

Suggested Fix

• Lazy-load subcommand modules (only load when actually invoked, not for --help)
• Defer any network calls (update checks, telemetry) until after help is rendered
• Profile the startup path to identify the bottleneck