Contract: one change page. The studio's change page carries the diff and review as its Files step #628

Pillar: P1 Feed (umbrella #587). Contract: one of the duplicated screens the studio/dev split left behind. One run, fresh from today's main.

The job: understand a pull and land or stop it.

Survivor: the studio change page (src/web/studio/change.ts) with dev's diff, review threads and merge controls as its Files step on the same page (an anchor or tab, no mode).

Removed in this same pull: dev's pull page header, meta and summary in src/web/pages/pull.ts that repeat the change page, and the "Read the code ?mode=dev" link. The diff view itself stays (src/web/diff-view.ts).

The path: the owner from a crew post or the board wants to decide on a change; primary action Ship (or say what to change); next back to the feed.

Acceptance.

• [ ] One renderer for this job, for every repository and every viewer; the other code and its tests are deleted, not hidden.
• [ ] Every old URL still answers (the survivor, or a redirect); ?mode=dev on it shows the survivor.
• [ ] Nothing the removed screen did is lost: the pull lists each thing it showed or did and where it lives now (or why nobody needs it).
• [ ] Minimal, not bare: one primary next action, white space at every width, nothing the person does not need now.
• [ ] Looks of the path at phone and desktop widths on the pull; the full check green.

Start from: src/web/studio/change.ts, src/web/pages/pull.ts, src/web/diff-view.ts.

Must not touch: the release workflow, the chart, other repositories.