feat: clarify Tailwind CSS behavior in setup prompts and documentation

[TangoPJ]

Problem:
When creating a project, the setup prompt asks whether to use Tailwind CSS.
Even if the user selects "No", Tailwind CSS is automatically enabled when add-ons are selected, which can be confusing

Changes made:

• Updated the Tailwind CSS prompt in packages/cta-cli/src/ui-prompts.ts to clarify this behavior
• Added a note in Architecture.md explaining that Tailwind CSS is enabled automatically if add-ons are chosen

Impact:
Improves UX and documentation for new users without changing existing functionality

[jherr]

Very cool. Unfortunately we already have a PR in flight that will make no tailwind a legit option (meaning that only add-ons that require tailwind will trigger auto-tailwind) #151