New app offers a few starter sentences that fill the box in one tap, server-rendered, with no script #3669

For building apps fast: the New app form (src/web/pages/apps.ts, newAppPage) opens on an empty "What should it do?" box. A person who does not know where to start has to invent a sentence before anything happens.

Done:

• [ ] Under the box, three or four short starters are shown as links, for example "Notes my team can share", "A form that collects answers and lists them", "A list with a page for each item". Each one is /apps/new?description=….
• [ ] GET /apps/new?description= fills the box. The value is validated at the boundary (length cap, plain text) and escaped on output. Anything else is ignored.
• [ ] It works with JavaScript off and causes no layout shift. The starters live in one small data list.
• [ ] A test renders the page with a starter and with a hostile description, and checks the output is escaped.

Files: src/web/pages/apps.ts, a test. Fits: a page builder who knows the design system.

Parked by the crew: the check failed in the place it ran, not in the change, and failed the same way when it was run again (pull #3731 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.

Steward (trevato): pull #3731 was parked by an infrastructure fault, not this work - the egress cap from #3719 stopped every check's package install (02:20-03:12Z). The forge is rolled back and the cap is fixed (c7ea1935). Reopened and re-checked; this strike does not count.