[README] Missing bun install step in development instructions

Description:
Following the README's Development section exactly as written results in an error when running moon run web:dev. proto use correctly installs Bun itself (along with the other pinned tools from .prototools), but it does not install the project's dependencies via bun install. The README never mentions this step.

Steps to reproduce after installing proto:

cd /OpenCut
proto use
moon run web:dev

Result:
`

Root cause

The README jumps straight from proto use to moon run web:dev with no bun install step in between.

the working fix is:

cd apps/web
bun install
cd ../..
moon run web:dev

Suggested README fix

Add an explicit bun install step (run inside each app directory, e.g. apps/web) before the moon run *:dev commands.

Offer:
Happy to submit a PR with a corrected setup section if useful, even given the current contribution freeze

Open the README Development section and follow the documented setup through proto use and moon run web:dev. Update the instructions to include bun install in the relevant app directory, such as apps/web, before the development command. Verify the documented sequence matches the working commands described in the issue.