feat(extension): inject Mergify row into every merge box variant

[sileht]

GitHub serves PR pages with up to three different merge-box layouts
right now:

1. The new merge-status sidebar (a Primer dialog at the document
   root, anchored on [data-testid="mergebox-border-container"]),
   being rolled out.
2. The current bottom merge box ([data-testid="mergebox-partial"]
   with .border.rounded-2, optionally wrapped by
   .discussion-timeline-actions .merge-pr).
3. The classic .mergeability-details merge box.

Some users only see one variant; others — depending on the rollout —
see the new sidebar alongside the bottom merge box on the same page.
The extension needs to render the Mergify row on every variant so the
queue/refresh affordance is visible wherever GitHub shows merge
controls.

Refactor injectRowIntoMergeBox around a MERGE_BOX_ANCHORS table that
walks every variant and attaches a row to every container that does
not already contain one. The single-row id is replaced by a
data-mergify-merge-box-row attribute since multiple instances must
coexist; updateMergifyRow callers route through a new
updateAllMergifyRows helper so post-command refreshes and the
queue-state poll cover every instance.

While there, fix a latent collision: GitHub's new sidebar renders a
native <section id="mergify"> for the Mergify GitHub App check,
which made the previous document.querySelector("#mergify") gate
short-circuit our injection logic to update that native section
instead of our row. The attribute-based marker sidesteps that, and
the per-container guard inside injectRowIntoMergeBox keeps the
function idempotent on repeated MutationObserver ticks.

Tests cover the new sidebar anchor, coexistence with the native
<section id="mergify">, the legacy mergebox-partial fallback, the
no-merge-box case, multi-anchor coexistence (all three injected at
once), and per-anchor idempotency on repeated calls.

Fixes MRGFY-7396

Co-Authored-By: Claude Opus 4.7 (1M context) noreply@anthropic.com

[mergify]

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[Copilot]

Pull request overview

Adds support for GitHub’s updated PR merge-status sidebar so the Mergify merge-box row is injected into the new stable container and no longer collides with GitHub’s native section#mergify.

Changes:

• Updates merge-box row ID references to mergify-merge-box-row.
• Adds the new data-testid="mergebox-border-container" injection anchor with legacy fallback.
• Adds unit coverage for new sidebar injection, native #mergify coexistence, fallback behavior, and missing merge-box handling.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/queue.js	Renames the injected row ID and updates queue row refresh lookups.
src/mergify.js	Exports and updates merge-box injection to use the new GitHub sidebar anchor.
src/__tests__/mergify.test.js	Adds direct tests for merge-box row injection behavior.

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[sileht]

Revision history

#	Type	Changes	Reason	Date
1	initial	67ea233		2026-05-27 13:35 UTC
2	content	67ea233 → c5c090a (raw)		2026-05-27 13:35 UTC
3	content	c5c090a → 2222c31 (raw)		2026-05-27 13:47 UTC
4	content	2222c31 → cd78694 (raw)		2026-05-27 13:59 UTC
5	content	cd78694 → a306b76 (raw)		2026-05-27 14:08 UTC
6	content	a306b76 → cecbe26 (raw)		2026-05-27 14:14 UTC
7	content	cecbe26 → ad598c6 (raw)		2026-05-27 14:16 UTC
8	content	ad598c6 → 21257fd (raw)		2026-05-27 14:19 UTC
9	content	21257fd → 1eb5a3f (raw)		2026-05-27 14:22 UTC
10	content	1eb5a3f → 24aca7a (raw)		2026-05-27 17:50 UTC

[sileht]

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-05-29 08:55 UTC · Rule: default
• ✅ Checks passed · on draft merge queue: embarking main (789d776) and #494 together #497
• ✅ Merged — 2026-05-29 08:58 UTC · at 24aca7a2eee74a285d320492b5957c7406925437 · squash

This pull request spent 2 minutes 23 seconds in the queue, including 1 minute 38 seconds running CI.

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