One screen answers “is everything fine?”: the asks inbox, reborn as all fine / these need you #346

Part of #334 (1): "one 'all fine / these need you' screen (the asks inbox, reborn)". Today what asks a person is spread over the studio's asks panel (src/web/studio/asks.ts), the dashboard's Needs you (src/web/pages/site.ts inbox) and the TUI dashboard's inbox.

Done when

• [ ] one page (the studio's asks, at a stable URL such as /asks) leads with a single sentence: All fine when nothing asks the viewer, otherwise N things need you followed by the existing decision cards
• [ ] for a site admin, each forge health needs sentence (from /api/v1/health) is a card on the same list, so one screen covers both the apps and the forge
• [ ] the dashboard's Needs you block links to this page instead of being a second, different list; one definition of what asks a person, in asks.ts
• [ ] the studio header's asks count and this page agree (a test asserts the same number)
• [ ] works without JavaScript; first paint server-rendered
• [ ] tests: empty state says All fine; a stopped pull is listed; a health problem is listed for an admin and not for anyone else

Files: src/web/studio/asks.ts, src/web/pages/site.ts, src/http/server.ts (route), tests; docs/STUDIO.md. Risks: tests that assert the old dashboard headings (see #290/#291) — update the ones this change makes wrong and say which. Brief: a studio builder.