ci: auto-sync prompt artifacts from upstream prompts.yml

.github/workflows/sync-upstream-prompts.yml

@@ -0,0 +1,79 @@
+name: Sync upstream prompt artifacts
+
+# The committed prompt artifacts (prototypes/docusaurus/src/constants/prompts.ts,
+# prototypes/docusaurus/static/prompts.json, prototypes/docusaurus/static/prompts/llms.txt)
+# are generated from react_on_rails `prompts.yml`. The site build regenerates
+# them and fails on drift (scripts/prepare-prompts.mjs), so when upstream
+# `prompts.yml` changes they go stale and every PR turns red. This job
+# regenerates them from react_on_rails main and opens a PR, mirroring
+# react_on_rails' own `update-llms-full.yml` bot.
+
+on:
+  schedule:
+    - cron: '40 4 * * *'
+  workflow_dispatch:
+  repository_dispatch:
+    types: [docs-updated]
+
+permissions:
+  contents: write
+  pull-requests: write
+
+concurrency:
+  group: sync-upstream-prompts
+  cancel-in-progress: false
+
+jobs:
+  sync-prompts:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          persist-credentials: false
+
+      - name: Setup Node
+        uses: actions/setup-node@v5
+        with:
+          node-version: 24
+
+      - name: Regenerate docs + prompt artifacts from react_on_rails main
+        run: npm run prepare
+        env:
+          REACT_ON_RAILS_REPO_URL: https://github.com/shakacode/react_on_rails.git
+          REACT_ON_RAILS_REF: main
+
+      - name: Detect prompt-artifact changes
+        id: changes
+        run: |
+          set -euo pipefail
+          paths="prototypes/docusaurus/src/constants/prompts.ts prototypes/docusaurus/static/prompts.json prototypes/docusaurus/static/prompts/llms.txt"
+          if git diff --quiet -- $paths; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            echo "Prompt artifacts already current."
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            echo "Prompt-artifact drift detected:"
+            git status --short -- $paths
+          fi
+
+      - name: Create pull request for regenerated prompt artifacts
+        if: steps.changes.outputs.changed == 'true'
+        uses: peter-evans/create-pull-request@67ccf781d68cd99b580ae25a5c18a1cc84ffff1f # v7.0.6
+        with:
+          token: ${{ github.token }}
+          branch: chore/sync-prompt-artifacts
+          delete-branch: true
+          title: 'chore: sync prompt artifacts from upstream prompts.yml'
+          commit-message: 'chore: sync prompt artifacts from upstream prompts.yml'
+          body: |
+            Regenerates the committed prompt artifacts from react_on_rails `prompts.yml`
+            so the `prepare:prompts` build guard stays green.
+
+            These files are generated by `npm run prepare:prompts`; do not edit by hand.
+
+            Opened automatically by the `Sync upstream prompt artifacts` workflow.
+          add-paths: |
+            prototypes/docusaurus/src/constants/prompts.ts
+            prototypes/docusaurus/static/prompts.json
+            prototypes/docusaurus/static/prompts/llms.txt