Forward merged docs(prompts): ... PR events to Alakai

Use this in target repositories that should trigger implementation-agent runs when a prompt PR is merged.

name: Forward merged docs(prompts) PR

on:
  pull_request:
    types: [closed]

jobs:
  forward:
    if: >
      github.event.pull_request.merged == true &&
      startsWith(github.event.pull_request.title, 'docs(prompts):')
    runs-on: ubuntu-latest
    steps:
      - name: Build payload
        id: payload
        env:
          PR_NUMBER: ${{ github.event.pull_request.number }}
          PR_TITLE: ${{ github.event.pull_request.title }}
          MERGE_SHA: ${{ github.event.pull_request.merge_commit_sha }}
          BASE_REF: ${{ github.event.pull_request.base.ref }}
          REPO_FULL_NAME: ${{ github.repository }}
        run: |
          payload="$(cat <<EOF
          {"action":"closed","repository":{"full_name":"$REPO_FULL_NAME"},"pull_request":{"number":$PR_NUMBER,"title":"$PR_TITLE","merged":true,"merge_commit_sha":"$MERGE_SHA","base":{"ref":"$BASE_REF"}}}
          EOF
          )"
          printf 'payload=%s\n' "$payload" >> "$GITHUB_OUTPUT"

      - name: Sign payload
        id: sign
        env:
          PAYLOAD: ${{ steps.payload.outputs.payload }}
          GITHUB_WEBHOOK_SECRET: ${{ secrets.GITHUB_WEBHOOK_SECRET }}
        run: |
          digest="$(printf '%s' "$PAYLOAD" | openssl dgst -sha256 -hmac "$GITHUB_WEBHOOK_SECRET" -hex | sed 's/^.* //')"
          printf 'signature=sha256=%s\n' "$digest" >> "$GITHUB_OUTPUT"

      - name: Send to Alakai
        env:
          PAYLOAD: ${{ steps.payload.outputs.payload }}
          SIGNATURE: ${{ steps.sign.outputs.signature }}
          ALAKAI_WEBHOOK_URL: ${{ secrets.ALAKAI_WEBHOOK_URL }}
        run: |
          curl -sS -X POST "$ALAKAI_WEBHOOK_URL" \
            -H "content-type: application/json" \
            -H "x-github-event: pull_request" \
            -H "x-hub-signature-256: $SIGNATURE" \
            --data "$PAYLOAD"

Required secrets in the target repository:

• GITHUB_WEBHOOK_SECRET (same value configured in Alakai)
• ALAKAI_WEBHOOK_URL (for example https://alakai.example.com/github/webhook)