Add PHP and laravel (artisan, sale) commands

Context

Running rtk discover on my project revealed that 284 out of 675 unhandled commands are Laravel Sail variants — making it the single largest savings opportunity not yet covered by RTK.

Top unhandled commands

What I'd expect

RTK wrappers similar to existing ones, e.g.:

rtk sail artisan <args>   →  vendor/bin/sail artisan <args>

rtk sail exec <args>      →  vendor/bin/sail exec <args>

rtk sail bin <args>       →  vendor/bin/sail bin <args>

rtk sail composer <args>  →  vendor/bin/sail composer <args>

Or alternatively — a generic rtk sail <subcommand> <args> that proxies all Sail subcommands.

Why it matters

Laravel Sail is the standard Docker-based dev environment for Laravel projects. These commands produce large tool_result outputs (test runners, psql sessions, code formatters), so RTK's token-saving behavior would be particularly valuable here.

The issue names no files or tests; start by locating the existing RTK command wrappers and the command-discovery or proxy entry point. Exercise the listed Sail commands, including artisan, exec, bin, and composer, and confirm that the chosen wrapper approach forwards arguments while providing RTK's output reduction; the issue leaves the specific-command versus generic-proxy design open.