Add Sail Support in Guidelines

[pushpak1300]

This update introduces first class Sail support across the guidelines.
When a project installs Boost with Sail enabled, agent instructions now automatically switch to Sail specific commands rather than native CLI commands.

Example guidelines

Before
- Run the minimum number of tests needed. Use php artisan test with a filename or filter.

After (Sail selected during boost:install)
- Run the minimum number of tests needed. Use vendor/bin/sail artisan test with a filename or filter.

Alongside these dynamic command replacements, this MR adds dedicated Sail usage guidance so LLM agents can reliably work inside Sail environments.

## Laravel Sail

- This project runs inside Laravel Sail's Docker containers. You must run commands through Sail.
- Start services with `vendor/bin/sail up -d` and stop them using `vendor/bin/sail stop`.
- Open the app in a browser with `vendor/bin/sail open`.
- Prefix PHP, Artisan, Composer and Node commands with `vendor/bin/sail`. For example:
  - `vendor/bin/sail artisan migrate`
  - `vendor/bin/sail composer install`
  - `vendor/bin/sail npm run dev`
  - `vendor/bin/sail php script.php`
- View all Sail commands by running `vendor/bin/sail` with no arguments.

[joetannenbaum]

Close, perhaps a bit more tweaking based on my comments. Let me know what you think.

[joetannenbaum]

Looks good, did some minor refactoring in a couple of places, let me know you object to any of the changes.

Let's try to internalize some of these smaller detail-oriented nits for future PRs: