Add a promote-to-production flow (beta → production) to the Play Store

.buildkite/commands/gather-production-candidate.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+set -eu
+
+# Determines the current beta build, opens the "confirm the release" block step, and posts to
+# Slack. No build — just gems + secrets.
+
+echo "--- :rubygems: Setting up Gems"
+install_gems
+
+echo "--- :closed_lock_with_key: Installing Secrets"
+bundle exec fastlane run configure_apply
+
+echo "--- :android: Gathering the production candidate and opening the block step"
+bundle exec fastlane gather_production_candidate

.buildkite/commands/promote-to-production.sh

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+#!/usr/bin/env bash
+
+set -eu
+
+# Releases the build gathered by the preceding step to the production track, once a developer has
+# confirmed the block step. The version code is passed as the first argument; the Yes/No
+# confirmation is read from Buildkite meta-data. No build — just gems + secrets.
+
+VERSION_CODE="${1:-}"
+
+# `production_ready_to_release` must stay in sync with PRODUCTION_CONFIRM_META_DATA_KEY in
+# fastlane/lanes/promote.rb, which is the key the block-step confirmation field writes.
+READY="$(buildkite-agent meta-data get "production_ready_to_release" --default "no")"
+
+if [[ "${READY}" != "yes" ]]; then
+  echo "--- :no_entry_sign: Release not confirmed (production_ready_to_release=${READY}); skipping."
+  exit 0
+fi
+
+if [[ -z "${VERSION_CODE}" ]]; then
+  echo "+++ :x: No version code was provided to release."
+  exit 1
+fi
+
+echo "--- :rubygems: Setting up Gems"
+install_gems
+
+echo "--- :closed_lock_with_key: Installing Secrets"
+bundle exec fastlane run configure_apply
+
+echo "--- :rocket: Releasing ${VERSION_CODE} to the production track"
+bundle exec fastlane promote_to_production version_code:"${VERSION_CODE}"

.buildkite/promote-production.yml

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+# yaml-language-server: $schema=https://raw.githubusercontent.com/buildkite/pipeline-schema/main/schema.json
+---
+
+# Production release — run manually via the `PIPELINE` env var. Determines the current beta build,
+# opens a block step to confirm the release, and releases it to the production track.
+
+agents:
+  queue: "android"
+
+steps:
+  - label: ":android: Gather build to release to production"
+    command: ".buildkite/commands/gather-production-candidate.sh"
+    plugins: [$CI_TOOLKIT]
+
+# Slack backstop for any failed build — its unique value is failures that abort before the lane runs
+# (gems/secrets) and can't self-report; on a lane failure it may also accompany the lane's own
+# message. Channel intentionally stays the test channel for now (see send_slack_message).
+notify:
+  - slack: "#test-wpmobile-slack-integration"
+    if: build.state == "failed"