Make it yours: one action forks any app into your forge, with its app, and lands you on it #606

Pillar: P2 Explorer (umbrella #588). One run, started fresh from today's main.

Outcome (what a person sees). On any app you can see, one button makes it yours: a fork in your forge, running as your app, following the original, and you land on it watching the first deploy.

Today. Forking a repository exists (POST /:owner/:name/fork); the app, its crew and its following are separate steps.

Acceptance.

• [ ] "Make it yours" on app pages and explore rows shows a short preview (what is copied: code and history; what is not: data and secrets), then forks into the viewer's account, registers the app, follows the original (tell me of updates by default), and lands on the new app page with its first deploy in the feed.
• [ ] The source is untouched; app data and secrets are never copied.
• [ ] The Friend test, in the pull: a second account makes one of trevato's public apps theirs in one action.

Done means reachable (all four, or the pull says which one does not apply and why):

• Page: the button on app pages
• MCP: make_it_yours {repo, dryRun}
• Test: dry-run then apply; data and secrets not copied; following set
• Look: the button and the landing, on the pull

Start from: src/actions/forks.ts, src/actions/apps.ts, src/core/following.ts, src/web/pages/apps-name.ts, src/http/api.ts, src/http/mcp.ts.

Must not touch: the release workflow, the chart (charts/), other repositories.

Added acceptance (owner's contract rule, now in the direction and docs/VISION.md):

• [ ] Contract: one interface per job. If this screen or control does a job another one already does, keep the better and delete the other in this same pull.
• [ ] Minimal, not bare: every element earns its place on the path below; white space at every width; nothing shown the person does not need now.
• [ ] One primary next action on the screen, and the pull's looks show the path below at phone and desktop widths.
• [ ] The pull says what it removes for every screen or control it adds.

The path: a person looking at someone's app wants their own; the one action is Make it yours; they land on their new app watching its first deploy.