Ship, decline, say and decide stay on the page they were taken from #1110

When the owner ships a change from the inbox or the feed, the forge takes him to the app. He wanted to tap the next decision. The owner opens the forge to make a few decisions and leave; every action that is a decision must leave him where he was, with the row updated in place and a one-line word of what happened, and a link if he wants to go look.

Done looks like:

• [ ] POST …/pulls/:number/ship, /state (close), /say, /review-state and the asks' decide routes answer a page request with a redirect back to the page the request came from (the back field the form carries, never the Referer alone), and a fetch request with the updated fragment for that row.
• [ ] The inbox and the feed row re-render in place through the live fragment system (data-live-src), so the next decision is already under the thumb.
• [ ] A flash says what happened in one sentence, with the one link that matters ("Shipped #1105 · see it live").
• [ ] test/web-apps.test.ts or test/asks.test.ts pins: ship from the home returns to the home; ship from the pull page stays on the pull page.

Files I expect: src/web/studio/actions.ts (flashOrJson, the back handling), the forms in src/web/pages/site.ts and src/web/studio/home.ts.

Parked by the crew: the check failed ("the studio > a decision lands back on the page it was taken from, and says so with a link") and the decider saw no point in another try (pull #1129 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.

Parked by the crew: the check failed ("a fork that follows its parent > a proposal names only what is actually ahead: work the parent already has is not listed again") and the decider saw no point in another try (pull #1424 closed).

Parked twice since a person last spoke here, so it is the planner's now. Every reason:

1. the check failed ("the studio > a decision lands back on the page it was taken from, and says so with a link") and the decider saw no point in another try (pull #1129 closed)
2. the check failed ("a fork that follows its parent > a proposal names only what is actually ahead: work the parent already has is not listed again") and the decider saw no point in another try (pull #1424 closed)

The planner splits it, replaces it with a fresh issue, or defers it; a person can also say what to try. Nothing starts here until then, and the board lists it.

replaced by #1567. Part of this is already on main (flashTo(ctx, back, …) in src/web/studio/actions.ts). #1567 narrows the work to ship and close from the inbox and the feed, with an open-redirect test. The other routes come after it.