A pull page's merge box draws §5's card, row and btn, and the merge-* classes leave src/web/pages/pull.ts #4398

Part one of #3867, which stayed red twice when it tried three pages, the stylesheet and screenshots in one pull. This part changes markup only, and only in src/web/pages/pull.ts.

Done:

• [ ] Every state of the merge box in src/web/pages/pull.ts (lines ~400–600: Merged, Closed without merging, Merge on the origin, Can't merge, Waiting on review, Waiting on checks, ready to merge) is drawn with §5's components from src/web/ui.ts (card or row, badge, btn) and §5 classes. Name which ones in the pull. None of merge-box, merge-form, merge-headline or merge-sub appears in the page's HTML.
• [ ] Every form posts the same fields to the same action, and every sentence a person reads is still there.
• [ ] Do not delete the stylesheet rules and do not edit docs/DESIGN.md; a later issue does that.
• [ ] A test renders the merge box in at least the ready, waiting-on-checks and merged states. It asserts the old class names are absent and the Merge form's action and fields are present.
• [ ] bun x tsc --noEmit, bun scripts/design-lint.ts and bun test test/pull*.test.ts test/design-lint.test.ts pass. The Files page's timing test in test/pull-timing.test.ts is load-sensitive. If only it fails, say so in the pull rather than editing it.

No screenshots: the sandbox has no browser.

Parked by the crew: the run ended without a pull: clone failed: fatal: unable to parse commit 1446f69e8ea54fbdf88845347be4133484fd163e warning: Clone succeeded, but checkout failed. You can inspect what was checked out with 'git status' and retry with 'git restore

Parked by the crew: the run ended without a pull: clone failed: fatal: unable to parse commit 1446f69e8ea54fbdf88845347be4133484fd163e warning: Clone succeeded, but checkout failed. You can inspect what was checked out with 'git status' and retry with 'git restore

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

1. the run ended without a pull: clone failed: fatal: unable to parse commit 1446f69e8ea54fbdf88845347be4133484fd163e warning: Clone succeeded, but checkout failed. You can inspect what was checked out with 'git status' and retry with 'git restore
2. the run ended without a pull: clone failed: fatal: unable to parse commit 1446f69e8ea54fbdf88845347be4133484fd163e warning: Clone succeeded, but checkout failed. You can inspect what was checked out with 'git status' and retry with 'git restore

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.

Steward (a person): this run failed to check out ("unable to parse commit 1446f69e") during the 0.7.231 rollout, 13:50-13:58Z - an infrastructure fault, not this work. Strike reset; run again.