add ai review workflow (#10394)

Integrate a generic review bot for new PR it can only be dispatched
manually in actions for now. We can enable it on new PRs or other
conditions later if needed.

Future tasks:

- command bot integration so non github org users can request review
- polkadot-sdk specific prompts

related: polkadot-fellows/runtimes#1012

---------

Co-authored-by: Bastian Köcher <[email protected]>
Co-authored-by: Bastian Köcher <[email protected]>

Author: xlc

.config/review.polkacodes.yml

@@ -0,0 +1,10 @@
+rules:
+  - repo: polka-codes/prompts
+    path: review/preamble.md
+    branch: master
+  - repo: polka-codes/prompts
+    path: review/rust.md
+    branch: master
+  - repo: polka-codes/prompts
+    path: review/polkadot-sdk.md
+    branch: master

.github/scripts/cmd/cmd.py

@@ -545,7 +545,7 @@ def main():
             # Output labels as JSON for GitHub Action
             import json
             labels_output = {"labels": final_labels}
-            print(f"LABELS_JSON: {json.dumps(labels_output)}")
+            print_and_log(f"LABELS_JSON: {json.dumps(labels_output)}")
         except ValueError as e:
             print_and_log(f'❌ {e}')
 

.github/workflows/ai-review.yml

@@ -0,0 +1,43 @@
+name: AI PR Review
+
+on:
+  # pull_request: # enable this when we think this is ready
+  #   types: [opened, ready_for_review]
+  workflow_dispatch:
+    inputs:
+      pr_number:
+        description: 'PR number to review'
+        required: true
+        type: number
+
+permissions:
+  contents: read
+  pull-requests: write
+
+concurrency:
+  group: review-pr-${{ github.event.inputs.pr_number || github.event.number }}
+  cancel-in-progress: true
+
+jobs:
+  review:
+    timeout-minutes: 10
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Process PR
+        uses: polka-codes/action@v2
+        with:
+          pr_number: ${{ github.event.inputs.pr_number || github.event.number }}
+          review: true
+          config: .config/review.polkacodes.yml
+        env:
+          POLKA_API_PROVIDER: google
+          POLKA_MODEL: gemini-3-pro-preview
+          GITHUB_TOKEN: ${{ github.token }}
+          POLKA_API_KEY: ${{ secrets.GEMINI_API_KEY }}
+          POLKA_BUDGET: 5
+

.github/workflows/cmd-run.yml

@@ -293,12 +293,19 @@ jobs:
           repository: ${{ env.REPO }}
           ref: ${{ env.PR_BRANCH }}
 
-      - name: Download all artifacts
+      - name: Download command-diff artifact
         uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6.0.0
         with:
           name: command-diff
           path: command-diff
 
+      - name: Download command-output artifact
+        if: startsWith(github.event.inputs.cmd, 'label')
+        uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6.0.0
+        with:
+          name: command-output
+          path: command-output
+
       - name: Apply labels for label command
         if: startsWith(github.event.inputs.cmd, 'label')
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
@@ -310,7 +317,7 @@ jobs:
             let labels = [];
 
             try {
-              const output = fs.readFileSync('/tmp/cmd/command_output.log', 'utf8');
+              const output = fs.readFileSync('command-output/command_output.log', 'utf8');
 
               // Parse JSON labels from output - look for "LABELS_JSON: {...}"
               const jsonMatch = output.match(/LABELS_JSON: (.+)/);