chore(ci): add dormant push-email notification workflow #1

	# SPDX-License-Identifier: MPL-2.0
	# Dormant push-email notification. ARMED by setting the repo variable
	# PUSH_EMAIL_ENABLED=true (the single on/off switch). Addresses are pre-filled;
	# sending needs the org SMTP secrets (SMTP_HOST/PORT/USER/PASS). Inherited by
	# new repos from the template; placed on existing repos by the farm sweep.
	name: Push email notification
	on:
	push: {}
	permissions:
	contents: read
	jobs:
	notify:
	name: Email on push
	if: ${{ vars.PUSH_EMAIL_ENABLED == 'true' }}
	runs-on: ubuntu-latest
	steps:
	- name: Send push notification email
	uses: dawidd6/action-send-mail@6e502825a508b867ab2954ad6343b68787624c01 # pinned
	with:
	server_address: ${{ secrets.SMTP_HOST }}
	server_port: ${{ secrets.SMTP_PORT }}
	secure: true
	username: ${{ secrets.SMTP_USER }}
	password: ${{ secrets.SMTP_PASS }}
	from: "GitHub Push <${{ secrets.SMTP_USER }}>"
	to: "jonathan.jewell@gmail.com j.d.a.jewell@open.ac.uk"
	subject: "[${{ github.repository }}] push to ${{ github.ref_name }} by ${{ github.actor }}"
	body: \|
	Repository: ${{ github.repository }}
	Branch: ${{ github.ref_name }}
	Pusher: ${{ github.actor }}
	Compare: ${{ github.event.compare }}
	Head msg: ${{ github.event.head_commit.message }}

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