Clarify default template and run hook docs

[mjackson]

This makes the default starter app and the remix/ui runtime hooks easier to understand without changing the starter page content.

• Routes the default remix new home page through the shared Document and Layout shell while preserving the existing welcome content, links, prompts, font loading, and entry script behavior.
• Inlines the server-side resolveFrame function in the renderToStream() options object so the default server render setup mirrors the browser run() setup shape.
• Adds JSDoc for the run() loadModule and resolveFrame hooks, including callback parameter and return guidance for client-entry hydration and browser-loaded frames.
• Adds change notes for the CLI scaffold update and UI editor-hint documentation.

[github-actions]

Preview Build Available

A preview build has been created for this PR. You can install it using:

pnpm install "remix-run/remix#preview/pr-11407&path:packages/remix"

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