Local Co-Hosted Dev Mode (Integration-Level)

## User story As an app developer, I want the CLI to provision a local co-hosted dev setup (Shop + App connected), so I can run both without manual networking or Docker configuration. This aims to address the following observation: Wants `app create` to create another project (so we have two), the shop and the app I've created, and I can hit "run" on both without having to change any code, webhook. Not trivial because of Docker; need to be network-connected to talk with each other. Needs to be reachable by browser client. People already have problems with setting up services. Our solution has been "OrbStack." A lot easier to create plugins. And users don't want to use hosting. To find out: cohosted apps, so we don't introduce the hosting complexity -- like a sidecar along with the shop. Was kind of the idea w/AppScripts. ## Acceptance criteria CLI sets up: - [ ] Shop - [ ] App container/process - [ ] Network connectivity between them - [ ] App is reachable via browser (public URL or local proxy). - [ ] Webhooks work without manual URL tweaking. - [ ] No Docker networking knowledge required. Could be another story: As an app developer, I want a co-hosted “sidecar” development mode, so I can avoid hosting complexity while developing apps locally.