chore: Avoid PR skill on other origins

[mvvmm]

Summary

Renames the PR skill to pr-mr, updates its references, and supports pull requests and merge requests through each repository's provider tooling.

[github-actions]

This pull request requires reviews from CODEOWNERS as it changes files that match the following patterns:

Pattern	Owners
*	@cloudflare/product-owners

[cloudflare-workers-and-pages]

🚀 Deploying Preview to Cloudflare 🚀

Preview URL: https://chore-pr-skill-origin-guard.previews.developers.cloudflare.com (commit 6ebbebe)

This URL reflects your latest Preview deployment

Preview Deployments by commit

Status	Deployment URL	Commit	Updated (UTC)	See this deployment's details
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://f54ac85b.previews.developers.cloudflare.com	6ebbebe	2026-09-09T19:40:27.014Z	Visit the dashboard ↗
Build: In progress 🔵 View logs ↗		d5d3d73	2026-09-09T19:26:22.098Z	View logs ↗
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://2047115d.previews.developers.cloudflare.com	1f9e34e	2026-09-09T17:52:04.394Z	Visit the dashboard ↗
Build: Success ✅ Deployment: Success ✅ View logs ↗	https://45a2e95e.previews.developers.cloudflare.com	fdd4b29	2026-09-09T17:04:22.566Z	Visit the dashboard ↗
Build: In progress 🔵 View logs ↗		21492da	2026-09-09T15:58:50.802Z	View logs ↗

[cloudflare-docs-bot]

Review

✅ No issues found in commit 6ebbebe.

Code Review

This code review is in beta and may not always be helpful — use your judgment.

_{No code review issues found.}

Conventions

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Style Guide Review

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Commands

Only codeowners can run commands. Post a comment with the command to trigger it.

Command	Description
/review	Runs a review now. Incremental if a prior review exists, full if not.
/full-review	Re-reviews the entire PR diff from scratch, ignoring incremental history. Useful after a rebase, when you want a fresh review, or if the bot gets out of sync and reports issues that no longer exist.
/ignore-review-limit	Permanently lifts the 2-review automatic limit for this PR. Future pushes will trigger reviews as normal.
/disable-auto-review	Stops automatic reviews from triggering on future pushes to this PR. Codeowners can still run /review or /full-review manually.
/rebase	Rebases the PR branch against production. On conflict, attempts to resolve automatically using AI. Stops with an explanation if confidence is not high enough.

[github-actions]

Preview URL: https://6ebbebeb.preview.developers.cloudflare.com
Preview Branch URL: https://chore-pr-skill-origin-guard.preview.developers.cloudflare.com