fix(cli): shorten serve argv

[7ttp]

TL;DR

fixes a regression in supabase functions serve by removing the bundled Edge Runtime bootstrap script from the spawned docker run ... sh -c ... argv and mounting it into the container as /root/index.ts instead

This keeps the startup command small, preserves the runtime behavior, and avoids the ENAMETOOLONG: name too long, uv_spawn failure...

What's fixed?

functions serve ts path was embedding the full bundled runtime template directly into the docker entrypoint command

on win, that made the final spawn argv large enough to fail before docker even started,
which surfaced as ENAMETOOLONG: name too long, uv_spawn

Before:

the runtime template was embedded directly into the docker startup command and hit spawn length limits

After:

the template is mounted from a temp file, so the startup command stays short

ref:

• closes ENAMETOOLONG #5711