feat: draft PR in blockCTATransitions when package.json engines is changed (#2229)

## PR Checklist

- [x] Addresses an existing open issue: fixes #2185
- [x] That issue was marked as [`status: accepting
prs`](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aopen+is%3Aissue+label%3A%22status%3A+accepting+prs%22)
- [x] Steps in
[CONTRIBUTING.md](https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/.github/CONTRIBUTING.md)
were taken

## Overview

Goes with the suggested strategy in
#2185 (comment)
of, once per PR that changes `engines`:

1. Switching the PR to draft
2. Posting a comment explaining that it changes engines

🎁

Author: JoshuaKGoldberg

src/blocks/blockCTATransitions.test.ts

@@ -32,6 +32,11 @@ describe("blockCTATransitions", () => {
 			      "transition": {
 			        "action.yml": "description: Runs create-typescript-app in transition mode
 
+			inputs:
+			  token:
+			    description: GitHub personal access token with repo, workflow, and read:org permissions.
+			    required: true
+
 			name: Transition
 
 			runs:
@@ -59,6 +64,19 @@ describe("blockCTATransitions", () => {
 			           — _The Friendly Bingo Bot_ 💝
 
 			          > ℹ️ These automatic commits keep your repository up-to-date with new versions of [create-typescript-app](https://github.com/JoshuaKGoldberg/create-typescript-app). If you want to opt out, delete your \`.github/workflows/cta-transitions.yml\` file.
+			    - id: package-change
+			      uses: JoshuaKGoldberg/[email protected]
+			      with:
+			        properties: engines
+			    - if: steps.package-change.outputs.changed == 'true'
+			      uses: JoshuaKGoldberg/[email protected]
+			      with:
+			        github-token: \${{ inputs.token }}
+			        message: |-
+			          🤖 Beep boop! This PR changes the \`engines\` field in \`package.json\`. That might be a breaking change. It's been set to a draft so that it doesn't automatically merge. Go ahead and un-draft the PR if the change is ready for release.
+
+			          Cheers!
+			           — _The Friendly Bingo Bot_ 💝
 			  using: composite
 			",
 			      },
@@ -79,6 +97,8 @@ describe("blockCTATransitions", () => {
 			          token: \${{ secrets.ACCESS_TOKEN }}
 			      - if: steps.checkout.outcome != 'skipped'
 			        uses: ./.github/actions/transition
+			        with:
+			          token: \${{ secrets.ACCESS_TOKEN }}
 			      - if: steps.checkout.outcome == 'skipped'
 			        run: echo 'Skipping transition mode because the PR does not appear to be an automated or owner-created update to create-typescript-app.'
 

src/blocks/blockCTATransitions.ts

@@ -30,6 +30,13 @@ export const blockCTATransitions = base.createBlock({
 						transition: {
 							"action.yml": formatYaml({
 								description: "Runs create-typescript-app in transition mode",
+								inputs: {
+									token: {
+										description:
+											"GitHub personal access token with repo, workflow, and read:org permissions.",
+										required: true,
+									},
+								},
 								name: "Transition",
 								runs: {
 									steps: [
@@ -75,6 +82,34 @@ export const blockCTATransitions = base.createBlock({
 												].join("\n"),
 											},
 										},
+										{
+											id: "package-change",
+											uses: resolveUses(
+												"JoshuaKGoldberg/package-change-detector-action",
+												"0.1.0",
+												options.workflowsVersions,
+											),
+											with: {
+												properties: "engines",
+											},
+										},
+										{
+											if: `steps.package-change.outputs.changed == 'true'`,
+											uses: resolveUses(
+												"JoshuaKGoldberg/draft-pull-request-once-action",
+												"0.0.1",
+												options.workflowsVersions,
+											),
+											with: {
+												"github-token": "${{ inputs.token }}",
+												message: [
+													"🤖 Beep boop! This PR changes the `engines` field in `package.json`. That might be a breaking change. It's been set to a draft so that it doesn't automatically merge. Go ahead and un-draft the PR if the change is ready for release.",
+													"",
+													"Cheers!",
+													" — _The Friendly Bingo Bot_ 💝",
+												].join("\n"),
+											},
+										},
 									],
 									using: "composite",
 								},
@@ -113,6 +148,9 @@ export const blockCTATransitions = base.createBlock({
 								{
 									if: "steps.checkout.outcome != 'skipped'",
 									uses: "./.github/actions/transition",
+									with: {
+										token: "${{ secrets.ACCESS_TOKEN }}",
+									},
 								},
 								{
 									if: "steps.checkout.outcome == 'skipped'",