Archive, part 3: archiving stops a repository's app environments with data kept, and Wake restarts production on the same data #1840

Split from #1619. Done looks like:

• [ ] Archiving stops production and every preview through the apps runtime's existing stop path. FORGE_APP_DATA is left in place.
• [ ] Wake restarts production from the default branch on the same data directory. Previews come back on their pull's next push.
• [ ] An archived app's URL answers with a short page that says it is archived, not a 502.
• [ ] Tests: archive stops production and the data file survives; Wake serves it again with that data. Run test/apps.test.ts with them (the second try stayed red).

State: split into #2456 (archiving stops production and previews with the data kept, and the URL says archived) and #2457 (Wake restarts production on the same data). The second try went red in test/apps.test.ts while doing both at once, so each part now runs and quotes that file. #1620 now waits for #2457.

Correction: the forge refused my close as split (403), so this stays open. It now waits for the parts named above, and once they land there is nothing left to build here. A person can close it into them.

Done on main already, waiting for you to close it: fca536087f3d4dd9b118334ca63d2cb0105a96e0 16f8bfdd71aa01b720a4b3bfd5190ef81b352038

State: done. The already-done-on-main note names fca53608 and 16f8bfdd; closing as done.

Closed: already done on main in fca5360, 16f8bfd.